Coverage for /home/martinb/.local/share/virtualenvs/camcops/lib/python3.6/site-packages/scipy/constants/codata.py : 84%

Hot-keys on this page
r m x p toggle line displays
j k next/prev highlighted chunk
0 (zero) top of page
1 (one) first highlighted chunk
1# Compiled by Charles Harris, dated October 3, 2002
2# updated to 2002 values by BasSw, 2006
3# Updated to 2006 values by Vincent Davis June 2010
4# Updated to 2014 values by Joseph Booker, 2015
5# Updated to 2018 values by Jakob Jakobson, 2019
7"""
8Fundamental Physical Constants
9------------------------------
11These constants are taken from CODATA Recommended Values of the Fundamental
12Physical Constants 2018.
14Object
15------
16physical_constants : dict
17 A dictionary containing physical constants. Keys are the names of physical
18 constants, values are tuples (value, units, precision).
20Functions
21---------
22value(key):
23 Returns the value of the physical constant(key).
24unit(key):
25 Returns the units of the physical constant(key).
26precision(key):
27 Returns the relative precision of the physical constant(key).
28find(sub):
29 Prints or returns list of keys containing the string sub, default is all.
31Source
32------
33The values of the constants provided at this site are recommended for
34international use by CODATA and are the latest available. Termed the "2018
35CODATA recommended values," they are generally recognized worldwide for use in
36all fields of science and technology. The values became available on 20 May
372019 and replaced the 2014 CODATA set. Also available is an introduction to the
38constants for non-experts at
40https://physics.nist.gov/cuu/Constants/introduction.html
42References
43----------
44Theoretical and experimental publications relevant to the fundamental constants
45and closely related precision measurements published since the mid 1980s, but
46also including many older papers of particular interest, some of which date
47back to the 1800s. To search the bibliography, visit
49https://physics.nist.gov/cuu/Constants/
51"""
52import warnings
53from math import pi, sqrt
55__all__ = ['physical_constants', 'value', 'unit', 'precision', 'find',
56 'ConstantWarning']
58"""
59Source: https://physics.nist.gov/cuu/Constants/
61The values of the constants provided at this site are recommended for
62international use by CODATA and are the latest available. Termed the "2018
63CODATA recommended values," they are generally recognized worldwide for use in
64all fields of science and technology. The values became available on 20 May
652019 and replaced the 2014 CODATA set.
66"""
68#
69# Source: https://physics.nist.gov/cuu/Constants/
70#
72# Quantity Value Uncertainty Unit
73# ---------------------------------------------------- --------------------- -------------------- -------------
74txt2002 = """\
75Wien displacement law constant 2.897 7685e-3 0.000 0051e-3 m K
76atomic unit of 1st hyperpolarizablity 3.206 361 51e-53 0.000 000 28e-53 C^3 m^3 J^-2
77atomic unit of 2nd hyperpolarizablity 6.235 3808e-65 0.000 0011e-65 C^4 m^4 J^-3
78atomic unit of electric dipole moment 8.478 353 09e-30 0.000 000 73e-30 C m
79atomic unit of electric polarizablity 1.648 777 274e-41 0.000 000 016e-41 C^2 m^2 J^-1
80atomic unit of electric quadrupole moment 4.486 551 24e-40 0.000 000 39e-40 C m^2
81atomic unit of magn. dipole moment 1.854 801 90e-23 0.000 000 16e-23 J T^-1
82atomic unit of magn. flux density 2.350 517 42e5 0.000 000 20e5 T
83deuteron magn. moment 0.433 073 482e-26 0.000 000 038e-26 J T^-1
84deuteron magn. moment to Bohr magneton ratio 0.466 975 4567e-3 0.000 000 0050e-3
85deuteron magn. moment to nuclear magneton ratio 0.857 438 2329 0.000 000 0092
86deuteron-electron magn. moment ratio -4.664 345 548e-4 0.000 000 050e-4
87deuteron-proton magn. moment ratio 0.307 012 2084 0.000 000 0045
88deuteron-neutron magn. moment ratio -0.448 206 52 0.000 000 11
89electron gyromagn. ratio 1.760 859 74e11 0.000 000 15e11 s^-1 T^-1
90electron gyromagn. ratio over 2 pi 28 024.9532 0.0024 MHz T^-1
91electron magn. moment -928.476 412e-26 0.000 080e-26 J T^-1
92electron magn. moment to Bohr magneton ratio -1.001 159 652 1859 0.000 000 000 0038
93electron magn. moment to nuclear magneton ratio -1838.281 971 07 0.000 000 85
94electron magn. moment anomaly 1.159 652 1859e-3 0.000 000 0038e-3
95electron to shielded proton magn. moment ratio -658.227 5956 0.000 0071
96electron to shielded helion magn. moment ratio 864.058 255 0.000 010
97electron-deuteron magn. moment ratio -2143.923 493 0.000 023
98electron-muon magn. moment ratio 206.766 9894 0.000 0054
99electron-neutron magn. moment ratio 960.920 50 0.000 23
100electron-proton magn. moment ratio -658.210 6862 0.000 0066
101magn. constant 12.566 370 614...e-7 0 N A^-2
102magn. flux quantum 2.067 833 72e-15 0.000 000 18e-15 Wb
103muon magn. moment -4.490 447 99e-26 0.000 000 40e-26 J T^-1
104muon magn. moment to Bohr magneton ratio -4.841 970 45e-3 0.000 000 13e-3
105muon magn. moment to nuclear magneton ratio -8.890 596 98 0.000 000 23
106muon-proton magn. moment ratio -3.183 345 118 0.000 000 089
107neutron gyromagn. ratio 1.832 471 83e8 0.000 000 46e8 s^-1 T^-1
108neutron gyromagn. ratio over 2 pi 29.164 6950 0.000 0073 MHz T^-1
109neutron magn. moment -0.966 236 45e-26 0.000 000 24e-26 J T^-1
110neutron magn. moment to Bohr magneton ratio -1.041 875 63e-3 0.000 000 25e-3
111neutron magn. moment to nuclear magneton ratio -1.913 042 73 0.000 000 45
112neutron to shielded proton magn. moment ratio -0.684 996 94 0.000 000 16
113neutron-electron magn. moment ratio 1.040 668 82e-3 0.000 000 25e-3
114neutron-proton magn. moment ratio -0.684 979 34 0.000 000 16
115proton gyromagn. ratio 2.675 222 05e8 0.000 000 23e8 s^-1 T^-1
116proton gyromagn. ratio over 2 pi 42.577 4813 0.000 0037 MHz T^-1
117proton magn. moment 1.410 606 71e-26 0.000 000 12e-26 J T^-1
118proton magn. moment to Bohr magneton ratio 1.521 032 206e-3 0.000 000 015e-3
119proton magn. moment to nuclear magneton ratio 2.792 847 351 0.000 000 028
120proton magn. shielding correction 25.689e-6 0.015e-6
121proton-neutron magn. moment ratio -1.459 898 05 0.000 000 34
122shielded helion gyromagn. ratio 2.037 894 70e8 0.000 000 18e8 s^-1 T^-1
123shielded helion gyromagn. ratio over 2 pi 32.434 1015 0.000 0028 MHz T^-1
124shielded helion magn. moment -1.074 553 024e-26 0.000 000 093e-26 J T^-1
125shielded helion magn. moment to Bohr magneton ratio -1.158 671 474e-3 0.000 000 014e-3
126shielded helion magn. moment to nuclear magneton ratio -2.127 497 723 0.000 000 025
127shielded helion to proton magn. moment ratio -0.761 766 562 0.000 000 012
128shielded helion to shielded proton magn. moment ratio -0.761 786 1313 0.000 000 0033
129shielded helion gyromagn. ratio 2.037 894 70e8 0.000 000 18e8 s^-1 T^-1
130shielded helion gyromagn. ratio over 2 pi 32.434 1015 0.000 0028 MHz T^-1
131shielded proton magn. moment 1.410 570 47e-26 0.000 000 12e-26 J T^-1
132shielded proton magn. moment to Bohr magneton ratio 1.520 993 132e-3 0.000 000 016e-3
133shielded proton magn. moment to nuclear magneton ratio 2.792 775 604 0.000 000 030
134{220} lattice spacing of silicon 192.015 5965e-12 0.000 0070e-12 m"""
136txt2006 = """\
137lattice spacing of silicon 192.015 5762 e-12 0.000 0050 e-12 m
138alpha particle-electron mass ratio 7294.299 5365 0.000 0031
139alpha particle mass 6.644 656 20 e-27 0.000 000 33 e-27 kg
140alpha particle mass energy equivalent 5.971 919 17 e-10 0.000 000 30 e-10 J
141alpha particle mass energy equivalent in MeV 3727.379 109 0.000 093 MeV
142alpha particle mass in u 4.001 506 179 127 0.000 000 000 062 u
143alpha particle molar mass 4.001 506 179 127 e-3 0.000 000 000 062 e-3 kg mol^-1
144alpha particle-proton mass ratio 3.972 599 689 51 0.000 000 000 41
145Angstrom star 1.000 014 98 e-10 0.000 000 90 e-10 m
146atomic mass constant 1.660 538 782 e-27 0.000 000 083 e-27 kg
147atomic mass constant energy equivalent 1.492 417 830 e-10 0.000 000 074 e-10 J
148atomic mass constant energy equivalent in MeV 931.494 028 0.000 023 MeV
149atomic mass unit-electron volt relationship 931.494 028 e6 0.000 023 e6 eV
150atomic mass unit-hartree relationship 3.423 177 7149 e7 0.000 000 0049 e7 E_h
151atomic mass unit-hertz relationship 2.252 342 7369 e23 0.000 000 0032 e23 Hz
152atomic mass unit-inverse meter relationship 7.513 006 671 e14 0.000 000 011 e14 m^-1
153atomic mass unit-joule relationship 1.492 417 830 e-10 0.000 000 074 e-10 J
154atomic mass unit-kelvin relationship 1.080 9527 e13 0.000 0019 e13 K
155atomic mass unit-kilogram relationship 1.660 538 782 e-27 0.000 000 083 e-27 kg
156atomic unit of 1st hyperpolarizability 3.206 361 533 e-53 0.000 000 081 e-53 C^3 m^3 J^-2
157atomic unit of 2nd hyperpolarizability 6.235 380 95 e-65 0.000 000 31 e-65 C^4 m^4 J^-3
158atomic unit of action 1.054 571 628 e-34 0.000 000 053 e-34 J s
159atomic unit of charge 1.602 176 487 e-19 0.000 000 040 e-19 C
160atomic unit of charge density 1.081 202 300 e12 0.000 000 027 e12 C m^-3
161atomic unit of current 6.623 617 63 e-3 0.000 000 17 e-3 A
162atomic unit of electric dipole mom. 8.478 352 81 e-30 0.000 000 21 e-30 C m
163atomic unit of electric field 5.142 206 32 e11 0.000 000 13 e11 V m^-1
164atomic unit of electric field gradient 9.717 361 66 e21 0.000 000 24 e21 V m^-2
165atomic unit of electric polarizability 1.648 777 2536 e-41 0.000 000 0034 e-41 C^2 m^2 J^-1
166atomic unit of electric potential 27.211 383 86 0.000 000 68 V
167atomic unit of electric quadrupole mom. 4.486 551 07 e-40 0.000 000 11 e-40 C m^2
168atomic unit of energy 4.359 743 94 e-18 0.000 000 22 e-18 J
169atomic unit of force 8.238 722 06 e-8 0.000 000 41 e-8 N
170atomic unit of length 0.529 177 208 59 e-10 0.000 000 000 36 e-10 m
171atomic unit of mag. dipole mom. 1.854 801 830 e-23 0.000 000 046 e-23 J T^-1
172atomic unit of mag. flux density 2.350 517 382 e5 0.000 000 059 e5 T
173atomic unit of magnetizability 7.891 036 433 e-29 0.000 000 027 e-29 J T^-2
174atomic unit of mass 9.109 382 15 e-31 0.000 000 45 e-31 kg
175atomic unit of momentum 1.992 851 565 e-24 0.000 000 099 e-24 kg m s^-1
176atomic unit of permittivity 1.112 650 056... e-10 (exact) F m^-1
177atomic unit of time 2.418 884 326 505 e-17 0.000 000 000 016 e-17 s
178atomic unit of velocity 2.187 691 2541 e6 0.000 000 0015 e6 m s^-1
179Avogadro constant 6.022 141 79 e23 0.000 000 30 e23 mol^-1
180Bohr magneton 927.400 915 e-26 0.000 023 e-26 J T^-1
181Bohr magneton in eV/T 5.788 381 7555 e-5 0.000 000 0079 e-5 eV T^-1
182Bohr magneton in Hz/T 13.996 246 04 e9 0.000 000 35 e9 Hz T^-1
183Bohr magneton in inverse meters per tesla 46.686 4515 0.000 0012 m^-1 T^-1
184Bohr magneton in K/T 0.671 7131 0.000 0012 K T^-1
185Bohr radius 0.529 177 208 59 e-10 0.000 000 000 36 e-10 m
186Boltzmann constant 1.380 6504 e-23 0.000 0024 e-23 J K^-1
187Boltzmann constant in eV/K 8.617 343 e-5 0.000 015 e-5 eV K^-1
188Boltzmann constant in Hz/K 2.083 6644 e10 0.000 0036 e10 Hz K^-1
189Boltzmann constant in inverse meters per kelvin 69.503 56 0.000 12 m^-1 K^-1
190characteristic impedance of vacuum 376.730 313 461... (exact) ohm
191classical electron radius 2.817 940 2894 e-15 0.000 000 0058 e-15 m
192Compton wavelength 2.426 310 2175 e-12 0.000 000 0033 e-12 m
193Compton wavelength over 2 pi 386.159 264 59 e-15 0.000 000 53 e-15 m
194conductance quantum 7.748 091 7004 e-5 0.000 000 0053 e-5 S
195conventional value of Josephson constant 483 597.9 e9 (exact) Hz V^-1
196conventional value of von Klitzing constant 25 812.807 (exact) ohm
197Cu x unit 1.002 076 99 e-13 0.000 000 28 e-13 m
198deuteron-electron mag. mom. ratio -4.664 345 537 e-4 0.000 000 039 e-4
199deuteron-electron mass ratio 3670.482 9654 0.000 0016
200deuteron g factor 0.857 438 2308 0.000 000 0072
201deuteron mag. mom. 0.433 073 465 e-26 0.000 000 011 e-26 J T^-1
202deuteron mag. mom. to Bohr magneton ratio 0.466 975 4556 e-3 0.000 000 0039 e-3
203deuteron mag. mom. to nuclear magneton ratio 0.857 438 2308 0.000 000 0072
204deuteron mass 3.343 583 20 e-27 0.000 000 17 e-27 kg
205deuteron mass energy equivalent 3.005 062 72 e-10 0.000 000 15 e-10 J
206deuteron mass energy equivalent in MeV 1875.612 793 0.000 047 MeV
207deuteron mass in u 2.013 553 212 724 0.000 000 000 078 u
208deuteron molar mass 2.013 553 212 724 e-3 0.000 000 000 078 e-3 kg mol^-1
209deuteron-neutron mag. mom. ratio -0.448 206 52 0.000 000 11
210deuteron-proton mag. mom. ratio 0.307 012 2070 0.000 000 0024
211deuteron-proton mass ratio 1.999 007 501 08 0.000 000 000 22
212deuteron rms charge radius 2.1402 e-15 0.0028 e-15 m
213electric constant 8.854 187 817... e-12 (exact) F m^-1
214electron charge to mass quotient -1.758 820 150 e11 0.000 000 044 e11 C kg^-1
215electron-deuteron mag. mom. ratio -2143.923 498 0.000 018
216electron-deuteron mass ratio 2.724 437 1093 e-4 0.000 000 0012 e-4
217electron g factor -2.002 319 304 3622 0.000 000 000 0015
218electron gyromag. ratio 1.760 859 770 e11 0.000 000 044 e11 s^-1 T^-1
219electron gyromag. ratio over 2 pi 28 024.953 64 0.000 70 MHz T^-1
220electron mag. mom. -928.476 377 e-26 0.000 023 e-26 J T^-1
221electron mag. mom. anomaly 1.159 652 181 11 e-3 0.000 000 000 74 e-3
222electron mag. mom. to Bohr magneton ratio -1.001 159 652 181 11 0.000 000 000 000 74
223electron mag. mom. to nuclear magneton ratio -1838.281 970 92 0.000 000 80
224electron mass 9.109 382 15 e-31 0.000 000 45 e-31 kg
225electron mass energy equivalent 8.187 104 38 e-14 0.000 000 41 e-14 J
226electron mass energy equivalent in MeV 0.510 998 910 0.000 000 013 MeV
227electron mass in u 5.485 799 0943 e-4 0.000 000 0023 e-4 u
228electron molar mass 5.485 799 0943 e-7 0.000 000 0023 e-7 kg mol^-1
229electron-muon mag. mom. ratio 206.766 9877 0.000 0052
230electron-muon mass ratio 4.836 331 71 e-3 0.000 000 12 e-3
231electron-neutron mag. mom. ratio 960.920 50 0.000 23
232electron-neutron mass ratio 5.438 673 4459 e-4 0.000 000 0033 e-4
233electron-proton mag. mom. ratio -658.210 6848 0.000 0054
234electron-proton mass ratio 5.446 170 2177 e-4 0.000 000 0024 e-4
235electron-tau mass ratio 2.875 64 e-4 0.000 47 e-4
236electron to alpha particle mass ratio 1.370 933 555 70 e-4 0.000 000 000 58 e-4
237electron to shielded helion mag. mom. ratio 864.058 257 0.000 010
238electron to shielded proton mag. mom. ratio -658.227 5971 0.000 0072
239electron volt 1.602 176 487 e-19 0.000 000 040 e-19 J
240electron volt-atomic mass unit relationship 1.073 544 188 e-9 0.000 000 027 e-9 u
241electron volt-hartree relationship 3.674 932 540 e-2 0.000 000 092 e-2 E_h
242electron volt-hertz relationship 2.417 989 454 e14 0.000 000 060 e14 Hz
243electron volt-inverse meter relationship 8.065 544 65 e5 0.000 000 20 e5 m^-1
244electron volt-joule relationship 1.602 176 487 e-19 0.000 000 040 e-19 J
245electron volt-kelvin relationship 1.160 4505 e4 0.000 0020 e4 K
246electron volt-kilogram relationship 1.782 661 758 e-36 0.000 000 044 e-36 kg
247elementary charge 1.602 176 487 e-19 0.000 000 040 e-19 C
248elementary charge over h 2.417 989 454 e14 0.000 000 060 e14 A J^-1
249Faraday constant 96 485.3399 0.0024 C mol^-1
250Faraday constant for conventional electric current 96 485.3401 0.0048 C_90 mol^-1
251Fermi coupling constant 1.166 37 e-5 0.000 01 e-5 GeV^-2
252fine-structure constant 7.297 352 5376 e-3 0.000 000 0050 e-3
253first radiation constant 3.741 771 18 e-16 0.000 000 19 e-16 W m^2
254first radiation constant for spectral radiance 1.191 042 759 e-16 0.000 000 059 e-16 W m^2 sr^-1
255hartree-atomic mass unit relationship 2.921 262 2986 e-8 0.000 000 0042 e-8 u
256hartree-electron volt relationship 27.211 383 86 0.000 000 68 eV
257Hartree energy 4.359 743 94 e-18 0.000 000 22 e-18 J
258Hartree energy in eV 27.211 383 86 0.000 000 68 eV
259hartree-hertz relationship 6.579 683 920 722 e15 0.000 000 000 044 e15 Hz
260hartree-inverse meter relationship 2.194 746 313 705 e7 0.000 000 000 015 e7 m^-1
261hartree-joule relationship 4.359 743 94 e-18 0.000 000 22 e-18 J
262hartree-kelvin relationship 3.157 7465 e5 0.000 0055 e5 K
263hartree-kilogram relationship 4.850 869 34 e-35 0.000 000 24 e-35 kg
264helion-electron mass ratio 5495.885 2765 0.000 0052
265helion mass 5.006 411 92 e-27 0.000 000 25 e-27 kg
266helion mass energy equivalent 4.499 538 64 e-10 0.000 000 22 e-10 J
267helion mass energy equivalent in MeV 2808.391 383 0.000 070 MeV
268helion mass in u 3.014 932 2473 0.000 000 0026 u
269helion molar mass 3.014 932 2473 e-3 0.000 000 0026 e-3 kg mol^-1
270helion-proton mass ratio 2.993 152 6713 0.000 000 0026
271hertz-atomic mass unit relationship 4.439 821 6294 e-24 0.000 000 0064 e-24 u
272hertz-electron volt relationship 4.135 667 33 e-15 0.000 000 10 e-15 eV
273hertz-hartree relationship 1.519 829 846 006 e-16 0.000 000 000010e-16 E_h
274hertz-inverse meter relationship 3.335 640 951... e-9 (exact) m^-1
275hertz-joule relationship 6.626 068 96 e-34 0.000 000 33 e-34 J
276hertz-kelvin relationship 4.799 2374 e-11 0.000 0084 e-11 K
277hertz-kilogram relationship 7.372 496 00 e-51 0.000 000 37 e-51 kg
278inverse fine-structure constant 137.035 999 679 0.000 000 094
279inverse meter-atomic mass unit relationship 1.331 025 0394 e-15 0.000 000 0019 e-15 u
280inverse meter-electron volt relationship 1.239 841 875 e-6 0.000 000 031 e-6 eV
281inverse meter-hartree relationship 4.556 335 252 760 e-8 0.000 000 000 030 e-8 E_h
282inverse meter-hertz relationship 299 792 458 (exact) Hz
283inverse meter-joule relationship 1.986 445 501 e-25 0.000 000 099 e-25 J
284inverse meter-kelvin relationship 1.438 7752 e-2 0.000 0025 e-2 K
285inverse meter-kilogram relationship 2.210 218 70 e-42 0.000 000 11 e-42 kg
286inverse of conductance quantum 12 906.403 7787 0.000 0088 ohm
287Josephson constant 483 597.891 e9 0.012 e9 Hz V^-1
288joule-atomic mass unit relationship 6.700 536 41 e9 0.000 000 33 e9 u
289joule-electron volt relationship 6.241 509 65 e18 0.000 000 16 e18 eV
290joule-hartree relationship 2.293 712 69 e17 0.000 000 11 e17 E_h
291joule-hertz relationship 1.509 190 450 e33 0.000 000 075 e33 Hz
292joule-inverse meter relationship 5.034 117 47 e24 0.000 000 25 e24 m^-1
293joule-kelvin relationship 7.242 963 e22 0.000 013 e22 K
294joule-kilogram relationship 1.112 650 056... e-17 (exact) kg
295kelvin-atomic mass unit relationship 9.251 098 e-14 0.000 016 e-14 u
296kelvin-electron volt relationship 8.617 343 e-5 0.000 015 e-5 eV
297kelvin-hartree relationship 3.166 8153 e-6 0.000 0055 e-6 E_h
298kelvin-hertz relationship 2.083 6644 e10 0.000 0036 e10 Hz
299kelvin-inverse meter relationship 69.503 56 0.000 12 m^-1
300kelvin-joule relationship 1.380 6504 e-23 0.000 0024 e-23 J
301kelvin-kilogram relationship 1.536 1807 e-40 0.000 0027 e-40 kg
302kilogram-atomic mass unit relationship 6.022 141 79 e26 0.000 000 30 e26 u
303kilogram-electron volt relationship 5.609 589 12 e35 0.000 000 14 e35 eV
304kilogram-hartree relationship 2.061 486 16 e34 0.000 000 10 e34 E_h
305kilogram-hertz relationship 1.356 392 733 e50 0.000 000 068 e50 Hz
306kilogram-inverse meter relationship 4.524 439 15 e41 0.000 000 23 e41 m^-1
307kilogram-joule relationship 8.987 551 787... e16 (exact) J
308kilogram-kelvin relationship 6.509 651 e39 0.000 011 e39 K
309lattice parameter of silicon 543.102 064 e-12 0.000 014 e-12 m
310Loschmidt constant (273.15 K, 101.325 kPa) 2.686 7774 e25 0.000 0047 e25 m^-3
311mag. constant 12.566 370 614... e-7 (exact) N A^-2
312mag. flux quantum 2.067 833 667 e-15 0.000 000 052 e-15 Wb
313molar gas constant 8.314 472 0.000 015 J mol^-1 K^-1
314molar mass constant 1 e-3 (exact) kg mol^-1
315molar mass of carbon-12 12 e-3 (exact) kg mol^-1
316molar Planck constant 3.990 312 6821 e-10 0.000 000 0057 e-10 J s mol^-1
317molar Planck constant times c 0.119 626 564 72 0.000 000 000 17 J m mol^-1
318molar volume of ideal gas (273.15 K, 100 kPa) 22.710 981 e-3 0.000 040 e-3 m^3 mol^-1
319molar volume of ideal gas (273.15 K, 101.325 kPa) 22.413 996 e-3 0.000 039 e-3 m^3 mol^-1
320molar volume of silicon 12.058 8349 e-6 0.000 0011 e-6 m^3 mol^-1
321Mo x unit 1.002 099 55 e-13 0.000 000 53 e-13 m
322muon Compton wavelength 11.734 441 04 e-15 0.000 000 30 e-15 m
323muon Compton wavelength over 2 pi 1.867 594 295 e-15 0.000 000 047 e-15 m
324muon-electron mass ratio 206.768 2823 0.000 0052
325muon g factor -2.002 331 8414 0.000 000 0012
326muon mag. mom. -4.490 447 86 e-26 0.000 000 16 e-26 J T^-1
327muon mag. mom. anomaly 1.165 920 69 e-3 0.000 000 60 e-3
328muon mag. mom. to Bohr magneton ratio -4.841 970 49 e-3 0.000 000 12 e-3
329muon mag. mom. to nuclear magneton ratio -8.890 597 05 0.000 000 23
330muon mass 1.883 531 30 e-28 0.000 000 11 e-28 kg
331muon mass energy equivalent 1.692 833 510 e-11 0.000 000 095 e-11 J
332muon mass energy equivalent in MeV 105.658 3668 0.000 0038 MeV
333muon mass in u 0.113 428 9256 0.000 000 0029 u
334muon molar mass 0.113 428 9256 e-3 0.000 000 0029 e-3 kg mol^-1
335muon-neutron mass ratio 0.112 454 5167 0.000 000 0029
336muon-proton mag. mom. ratio -3.183 345 137 0.000 000 085
337muon-proton mass ratio 0.112 609 5261 0.000 000 0029
338muon-tau mass ratio 5.945 92 e-2 0.000 97 e-2
339natural unit of action 1.054 571 628 e-34 0.000 000 053 e-34 J s
340natural unit of action in eV s 6.582 118 99 e-16 0.000 000 16 e-16 eV s
341natural unit of energy 8.187 104 38 e-14 0.000 000 41 e-14 J
342natural unit of energy in MeV 0.510 998 910 0.000 000 013 MeV
343natural unit of length 386.159 264 59 e-15 0.000 000 53 e-15 m
344natural unit of mass 9.109 382 15 e-31 0.000 000 45 e-31 kg
345natural unit of momentum 2.730 924 06 e-22 0.000 000 14 e-22 kg m s^-1
346natural unit of momentum in MeV/c 0.510 998 910 0.000 000 013 MeV/c
347natural unit of time 1.288 088 6570 e-21 0.000 000 0018 e-21 s
348natural unit of velocity 299 792 458 (exact) m s^-1
349neutron Compton wavelength 1.319 590 8951 e-15 0.000 000 0020 e-15 m
350neutron Compton wavelength over 2 pi 0.210 019 413 82 e-15 0.000 000 000 31 e-15 m
351neutron-electron mag. mom. ratio 1.040 668 82 e-3 0.000 000 25 e-3
352neutron-electron mass ratio 1838.683 6605 0.000 0011
353neutron g factor -3.826 085 45 0.000 000 90
354neutron gyromag. ratio 1.832 471 85 e8 0.000 000 43 e8 s^-1 T^-1
355neutron gyromag. ratio over 2 pi 29.164 6954 0.000 0069 MHz T^-1
356neutron mag. mom. -0.966 236 41 e-26 0.000 000 23 e-26 J T^-1
357neutron mag. mom. to Bohr magneton ratio -1.041 875 63 e-3 0.000 000 25 e-3
358neutron mag. mom. to nuclear magneton ratio -1.913 042 73 0.000 000 45
359neutron mass 1.674 927 211 e-27 0.000 000 084 e-27 kg
360neutron mass energy equivalent 1.505 349 505 e-10 0.000 000 075 e-10 J
361neutron mass energy equivalent in MeV 939.565 346 0.000 023 MeV
362neutron mass in u 1.008 664 915 97 0.000 000 000 43 u
363neutron molar mass 1.008 664 915 97 e-3 0.000 000 000 43 e-3 kg mol^-1
364neutron-muon mass ratio 8.892 484 09 0.000 000 23
365neutron-proton mag. mom. ratio -0.684 979 34 0.000 000 16
366neutron-proton mass ratio 1.001 378 419 18 0.000 000 000 46
367neutron-tau mass ratio 0.528 740 0.000 086
368neutron to shielded proton mag. mom. ratio -0.684 996 94 0.000 000 16
369Newtonian constant of gravitation 6.674 28 e-11 0.000 67 e-11 m^3 kg^-1 s^-2
370Newtonian constant of gravitation over h-bar c 6.708 81 e-39 0.000 67 e-39 (GeV/c^2)^-2
371nuclear magneton 5.050 783 24 e-27 0.000 000 13 e-27 J T^-1
372nuclear magneton in eV/T 3.152 451 2326 e-8 0.000 000 0045 e-8 eV T^-1
373nuclear magneton in inverse meters per tesla 2.542 623 616 e-2 0.000 000 064 e-2 m^-1 T^-1
374nuclear magneton in K/T 3.658 2637 e-4 0.000 0064 e-4 K T^-1
375nuclear magneton in MHz/T 7.622 593 84 0.000 000 19 MHz T^-1
376Planck constant 6.626 068 96 e-34 0.000 000 33 e-34 J s
377Planck constant in eV s 4.135 667 33 e-15 0.000 000 10 e-15 eV s
378Planck constant over 2 pi 1.054 571 628 e-34 0.000 000 053 e-34 J s
379Planck constant over 2 pi in eV s 6.582 118 99 e-16 0.000 000 16 e-16 eV s
380Planck constant over 2 pi times c in MeV fm 197.326 9631 0.000 0049 MeV fm
381Planck length 1.616 252 e-35 0.000 081 e-35 m
382Planck mass 2.176 44 e-8 0.000 11 e-8 kg
383Planck mass energy equivalent in GeV 1.220 892 e19 0.000 061 e19 GeV
384Planck temperature 1.416 785 e32 0.000 071 e32 K
385Planck time 5.391 24 e-44 0.000 27 e-44 s
386proton charge to mass quotient 9.578 833 92 e7 0.000 000 24 e7 C kg^-1
387proton Compton wavelength 1.321 409 8446 e-15 0.000 000 0019 e-15 m
388proton Compton wavelength over 2 pi 0.210 308 908 61 e-15 0.000 000 000 30 e-15 m
389proton-electron mass ratio 1836.152 672 47 0.000 000 80
390proton g factor 5.585 694 713 0.000 000 046
391proton gyromag. ratio 2.675 222 099 e8 0.000 000 070 e8 s^-1 T^-1
392proton gyromag. ratio over 2 pi 42.577 4821 0.000 0011 MHz T^-1
393proton mag. mom. 1.410 606 662 e-26 0.000 000 037 e-26 J T^-1
394proton mag. mom. to Bohr magneton ratio 1.521 032 209 e-3 0.000 000 012 e-3
395proton mag. mom. to nuclear magneton ratio 2.792 847 356 0.000 000 023
396proton mag. shielding correction 25.694 e-6 0.014 e-6
397proton mass 1.672 621 637 e-27 0.000 000 083 e-27 kg
398proton mass energy equivalent 1.503 277 359 e-10 0.000 000 075 e-10 J
399proton mass energy equivalent in MeV 938.272 013 0.000 023 MeV
400proton mass in u 1.007 276 466 77 0.000 000 000 10 u
401proton molar mass 1.007 276 466 77 e-3 0.000 000 000 10 e-3 kg mol^-1
402proton-muon mass ratio 8.880 243 39 0.000 000 23
403proton-neutron mag. mom. ratio -1.459 898 06 0.000 000 34
404proton-neutron mass ratio 0.998 623 478 24 0.000 000 000 46
405proton rms charge radius 0.8768 e-15 0.0069 e-15 m
406proton-tau mass ratio 0.528 012 0.000 086
407quantum of circulation 3.636 947 5199 e-4 0.000 000 0050 e-4 m^2 s^-1
408quantum of circulation times 2 7.273 895 040 e-4 0.000 000 010 e-4 m^2 s^-1
409Rydberg constant 10 973 731.568 527 0.000 073 m^-1
410Rydberg constant times c in Hz 3.289 841 960 361 e15 0.000 000 000 022 e15 Hz
411Rydberg constant times hc in eV 13.605 691 93 0.000 000 34 eV
412Rydberg constant times hc in J 2.179 871 97 e-18 0.000 000 11 e-18 J
413Sackur-Tetrode constant (1 K, 100 kPa) -1.151 7047 0.000 0044
414Sackur-Tetrode constant (1 K, 101.325 kPa) -1.164 8677 0.000 0044
415second radiation constant 1.438 7752 e-2 0.000 0025 e-2 m K
416shielded helion gyromag. ratio 2.037 894 730 e8 0.000 000 056 e8 s^-1 T^-1
417shielded helion gyromag. ratio over 2 pi 32.434 101 98 0.000 000 90 MHz T^-1
418shielded helion mag. mom. -1.074 552 982 e-26 0.000 000 030 e-26 J T^-1
419shielded helion mag. mom. to Bohr magneton ratio -1.158 671 471 e-3 0.000 000 014 e-3
420shielded helion mag. mom. to nuclear magneton ratio -2.127 497 718 0.000 000 025
421shielded helion to proton mag. mom. ratio -0.761 766 558 0.000 000 011
422shielded helion to shielded proton mag. mom. ratio -0.761 786 1313 0.000 000 0033
423shielded proton gyromag. ratio 2.675 153 362 e8 0.000 000 073 e8 s^-1 T^-1
424shielded proton gyromag. ratio over 2 pi 42.576 3881 0.000 0012 MHz T^-1
425shielded proton mag. mom. 1.410 570 419 e-26 0.000 000 038 e-26 J T^-1
426shielded proton mag. mom. to Bohr magneton ratio 1.520 993 128 e-3 0.000 000 017 e-3
427shielded proton mag. mom. to nuclear magneton ratio 2.792 775 598 0.000 000 030
428speed of light in vacuum 299 792 458 (exact) m s^-1
429standard acceleration of gravity 9.806 65 (exact) m s^-2
430standard atmosphere 101 325 (exact) Pa
431Stefan-Boltzmann constant 5.670 400 e-8 0.000 040 e-8 W m^-2 K^-4
432tau Compton wavelength 0.697 72 e-15 0.000 11 e-15 m
433tau Compton wavelength over 2 pi 0.111 046 e-15 0.000 018 e-15 m
434tau-electron mass ratio 3477.48 0.57
435tau mass 3.167 77 e-27 0.000 52 e-27 kg
436tau mass energy equivalent 2.847 05 e-10 0.000 46 e-10 J
437tau mass energy equivalent in MeV 1776.99 0.29 MeV
438tau mass in u 1.907 68 0.000 31 u
439tau molar mass 1.907 68 e-3 0.000 31 e-3 kg mol^-1
440tau-muon mass ratio 16.8183 0.0027
441tau-neutron mass ratio 1.891 29 0.000 31
442tau-proton mass ratio 1.893 90 0.000 31
443Thomson cross section 0.665 245 8558 e-28 0.000 000 0027 e-28 m^2
444triton-electron mag. mom. ratio -1.620 514 423 e-3 0.000 000 021 e-3
445triton-electron mass ratio 5496.921 5269 0.000 0051
446triton g factor 5.957 924 896 0.000 000 076
447triton mag. mom. 1.504 609 361 e-26 0.000 000 042 e-26 J T^-1
448triton mag. mom. to Bohr magneton ratio 1.622 393 657 e-3 0.000 000 021 e-3
449triton mag. mom. to nuclear magneton ratio 2.978 962 448 0.000 000 038
450triton mass 5.007 355 88 e-27 0.000 000 25 e-27 kg
451triton mass energy equivalent 4.500 387 03 e-10 0.000 000 22 e-10 J
452triton mass energy equivalent in MeV 2808.920 906 0.000 070 MeV
453triton mass in u 3.015 500 7134 0.000 000 0025 u
454triton molar mass 3.015 500 7134 e-3 0.000 000 0025 e-3 kg mol^-1
455triton-neutron mag. mom. ratio -1.557 185 53 0.000 000 37
456triton-proton mag. mom. ratio 1.066 639 908 0.000 000 010
457triton-proton mass ratio 2.993 717 0309 0.000 000 0025
458unified atomic mass unit 1.660 538 782 e-27 0.000 000 083 e-27 kg
459von Klitzing constant 25 812.807 557 0.000 018 ohm
460weak mixing angle 0.222 55 0.000 56
461Wien frequency displacement law constant 5.878 933 e10 0.000 010 e10 Hz K^-1
462Wien wavelength displacement law constant 2.897 7685 e-3 0.000 0051 e-3 m K"""
464txt2010 = """\
465{220} lattice spacing of silicon 192.015 5714 e-12 0.000 0032 e-12 m
466alpha particle-electron mass ratio 7294.299 5361 0.000 0029
467alpha particle mass 6.644 656 75 e-27 0.000 000 29 e-27 kg
468alpha particle mass energy equivalent 5.971 919 67 e-10 0.000 000 26 e-10 J
469alpha particle mass energy equivalent in MeV 3727.379 240 0.000 082 MeV
470alpha particle mass in u 4.001 506 179 125 0.000 000 000 062 u
471alpha particle molar mass 4.001 506 179 125 e-3 0.000 000 000 062 e-3 kg mol^-1
472alpha particle-proton mass ratio 3.972 599 689 33 0.000 000 000 36
473Angstrom star 1.000 014 95 e-10 0.000 000 90 e-10 m
474atomic mass constant 1.660 538 921 e-27 0.000 000 073 e-27 kg
475atomic mass constant energy equivalent 1.492 417 954 e-10 0.000 000 066 e-10 J
476atomic mass constant energy equivalent in MeV 931.494 061 0.000 021 MeV
477atomic mass unit-electron volt relationship 931.494 061 e6 0.000 021 e6 eV
478atomic mass unit-hartree relationship 3.423 177 6845 e7 0.000 000 0024 e7 E_h
479atomic mass unit-hertz relationship 2.252 342 7168 e23 0.000 000 0016 e23 Hz
480atomic mass unit-inverse meter relationship 7.513 006 6042 e14 0.000 000 0053 e14 m^-1
481atomic mass unit-joule relationship 1.492 417 954 e-10 0.000 000 066 e-10 J
482atomic mass unit-kelvin relationship 1.080 954 08 e13 0.000 000 98 e13 K
483atomic mass unit-kilogram relationship 1.660 538 921 e-27 0.000 000 073 e-27 kg
484atomic unit of 1st hyperpolarizability 3.206 361 449 e-53 0.000 000 071 e-53 C^3 m^3 J^-2
485atomic unit of 2nd hyperpolarizability 6.235 380 54 e-65 0.000 000 28 e-65 C^4 m^4 J^-3
486atomic unit of action 1.054 571 726 e-34 0.000 000 047 e-34 J s
487atomic unit of charge 1.602 176 565 e-19 0.000 000 035 e-19 C
488atomic unit of charge density 1.081 202 338 e12 0.000 000 024 e12 C m^-3
489atomic unit of current 6.623 617 95 e-3 0.000 000 15 e-3 A
490atomic unit of electric dipole mom. 8.478 353 26 e-30 0.000 000 19 e-30 C m
491atomic unit of electric field 5.142 206 52 e11 0.000 000 11 e11 V m^-1
492atomic unit of electric field gradient 9.717 362 00 e21 0.000 000 21 e21 V m^-2
493atomic unit of electric polarizability 1.648 777 2754 e-41 0.000 000 0016 e-41 C^2 m^2 J^-1
494atomic unit of electric potential 27.211 385 05 0.000 000 60 V
495atomic unit of electric quadrupole mom. 4.486 551 331 e-40 0.000 000 099 e-40 C m^2
496atomic unit of energy 4.359 744 34 e-18 0.000 000 19 e-18 J
497atomic unit of force 8.238 722 78 e-8 0.000 000 36 e-8 N
498atomic unit of length 0.529 177 210 92 e-10 0.000 000 000 17 e-10 m
499atomic unit of mag. dipole mom. 1.854 801 936 e-23 0.000 000 041 e-23 J T^-1
500atomic unit of mag. flux density 2.350 517 464 e5 0.000 000 052 e5 T
501atomic unit of magnetizability 7.891 036 607 e-29 0.000 000 013 e-29 J T^-2
502atomic unit of mass 9.109 382 91 e-31 0.000 000 40 e-31 kg
503atomic unit of mom.um 1.992 851 740 e-24 0.000 000 088 e-24 kg m s^-1
504atomic unit of permittivity 1.112 650 056... e-10 (exact) F m^-1
505atomic unit of time 2.418 884 326 502e-17 0.000 000 000 012e-17 s
506atomic unit of velocity 2.187 691 263 79 e6 0.000 000 000 71 e6 m s^-1
507Avogadro constant 6.022 141 29 e23 0.000 000 27 e23 mol^-1
508Bohr magneton 927.400 968 e-26 0.000 020 e-26 J T^-1
509Bohr magneton in eV/T 5.788 381 8066 e-5 0.000 000 0038 e-5 eV T^-1
510Bohr magneton in Hz/T 13.996 245 55 e9 0.000 000 31 e9 Hz T^-1
511Bohr magneton in inverse meters per tesla 46.686 4498 0.000 0010 m^-1 T^-1
512Bohr magneton in K/T 0.671 713 88 0.000 000 61 K T^-1
513Bohr radius 0.529 177 210 92 e-10 0.000 000 000 17 e-10 m
514Boltzmann constant 1.380 6488 e-23 0.000 0013 e-23 J K^-1
515Boltzmann constant in eV/K 8.617 3324 e-5 0.000 0078 e-5 eV K^-1
516Boltzmann constant in Hz/K 2.083 6618 e10 0.000 0019 e10 Hz K^-1
517Boltzmann constant in inverse meters per kelvin 69.503 476 0.000 063 m^-1 K^-1
518characteristic impedance of vacuum 376.730 313 461... (exact) ohm
519classical electron radius 2.817 940 3267 e-15 0.000 000 0027 e-15 m
520Compton wavelength 2.426 310 2389 e-12 0.000 000 0016 e-12 m
521Compton wavelength over 2 pi 386.159 268 00 e-15 0.000 000 25 e-15 m
522conductance quantum 7.748 091 7346 e-5 0.000 000 0025 e-5 S
523conventional value of Josephson constant 483 597.9 e9 (exact) Hz V^-1
524conventional value of von Klitzing constant 25 812.807 (exact) ohm
525Cu x unit 1.002 076 97 e-13 0.000 000 28 e-13 m
526deuteron-electron mag. mom. ratio -4.664 345 537 e-4 0.000 000 039 e-4
527deuteron-electron mass ratio 3670.482 9652 0.000 0015
528deuteron g factor 0.857 438 2308 0.000 000 0072
529deuteron mag. mom. 0.433 073 489 e-26 0.000 000 010 e-26 J T^-1
530deuteron mag. mom. to Bohr magneton ratio 0.466 975 4556 e-3 0.000 000 0039 e-3
531deuteron mag. mom. to nuclear magneton ratio 0.857 438 2308 0.000 000 0072
532deuteron mass 3.343 583 48 e-27 0.000 000 15 e-27 kg
533deuteron mass energy equivalent 3.005 062 97 e-10 0.000 000 13 e-10 J
534deuteron mass energy equivalent in MeV 1875.612 859 0.000 041 MeV
535deuteron mass in u 2.013 553 212 712 0.000 000 000 077 u
536deuteron molar mass 2.013 553 212 712 e-3 0.000 000 000 077 e-3 kg mol^-1
537deuteron-neutron mag. mom. ratio -0.448 206 52 0.000 000 11
538deuteron-proton mag. mom. ratio 0.307 012 2070 0.000 000 0024
539deuteron-proton mass ratio 1.999 007 500 97 0.000 000 000 18
540deuteron rms charge radius 2.1424 e-15 0.0021 e-15 m
541electric constant 8.854 187 817... e-12 (exact) F m^-1
542electron charge to mass quotient -1.758 820 088 e11 0.000 000 039 e11 C kg^-1
543electron-deuteron mag. mom. ratio -2143.923 498 0.000 018
544electron-deuteron mass ratio 2.724 437 1095 e-4 0.000 000 0011 e-4
545electron g factor -2.002 319 304 361 53 0.000 000 000 000 53
546electron gyromag. ratio 1.760 859 708 e11 0.000 000 039 e11 s^-1 T^-1
547electron gyromag. ratio over 2 pi 28 024.952 66 0.000 62 MHz T^-1
548electron-helion mass ratio 1.819 543 0761 e-4 0.000 000 0017 e-4
549electron mag. mom. -928.476 430 e-26 0.000 021 e-26 J T^-1
550electron mag. mom. anomaly 1.159 652 180 76 e-3 0.000 000 000 27 e-3
551electron mag. mom. to Bohr magneton ratio -1.001 159 652 180 76 0.000 000 000 000 27
552electron mag. mom. to nuclear magneton ratio -1838.281 970 90 0.000 000 75
553electron mass 9.109 382 91 e-31 0.000 000 40 e-31 kg
554electron mass energy equivalent 8.187 105 06 e-14 0.000 000 36 e-14 J
555electron mass energy equivalent in MeV 0.510 998 928 0.000 000 011 MeV
556electron mass in u 5.485 799 0946 e-4 0.000 000 0022 e-4 u
557electron molar mass 5.485 799 0946 e-7 0.000 000 0022 e-7 kg mol^-1
558electron-muon mag. mom. ratio 206.766 9896 0.000 0052
559electron-muon mass ratio 4.836 331 66 e-3 0.000 000 12 e-3
560electron-neutron mag. mom. ratio 960.920 50 0.000 23
561electron-neutron mass ratio 5.438 673 4461 e-4 0.000 000 0032 e-4
562electron-proton mag. mom. ratio -658.210 6848 0.000 0054
563electron-proton mass ratio 5.446 170 2178 e-4 0.000 000 0022 e-4
564electron-tau mass ratio 2.875 92 e-4 0.000 26 e-4
565electron to alpha particle mass ratio 1.370 933 555 78 e-4 0.000 000 000 55 e-4
566electron to shielded helion mag. mom. ratio 864.058 257 0.000 010
567electron to shielded proton mag. mom. ratio -658.227 5971 0.000 0072
568electron-triton mass ratio 1.819 200 0653 e-4 0.000 000 0017 e-4
569electron volt 1.602 176 565 e-19 0.000 000 035 e-19 J
570electron volt-atomic mass unit relationship 1.073 544 150 e-9 0.000 000 024 e-9 u
571electron volt-hartree relationship 3.674 932 379 e-2 0.000 000 081 e-2 E_h
572electron volt-hertz relationship 2.417 989 348 e14 0.000 000 053 e14 Hz
573electron volt-inverse meter relationship 8.065 544 29 e5 0.000 000 18 e5 m^-1
574electron volt-joule relationship 1.602 176 565 e-19 0.000 000 035 e-19 J
575electron volt-kelvin relationship 1.160 4519 e4 0.000 0011 e4 K
576electron volt-kilogram relationship 1.782 661 845 e-36 0.000 000 039 e-36 kg
577elementary charge 1.602 176 565 e-19 0.000 000 035 e-19 C
578elementary charge over h 2.417 989 348 e14 0.000 000 053 e14 A J^-1
579Faraday constant 96 485.3365 0.0021 C mol^-1
580Faraday constant for conventional electric current 96 485.3321 0.0043 C_90 mol^-1
581Fermi coupling constant 1.166 364 e-5 0.000 005 e-5 GeV^-2
582fine-structure constant 7.297 352 5698 e-3 0.000 000 0024 e-3
583first radiation constant 3.741 771 53 e-16 0.000 000 17 e-16 W m^2
584first radiation constant for spectral radiance 1.191 042 869 e-16 0.000 000 053 e-16 W m^2 sr^-1
585hartree-atomic mass unit relationship 2.921 262 3246 e-8 0.000 000 0021 e-8 u
586hartree-electron volt relationship 27.211 385 05 0.000 000 60 eV
587Hartree energy 4.359 744 34 e-18 0.000 000 19 e-18 J
588Hartree energy in eV 27.211 385 05 0.000 000 60 eV
589hartree-hertz relationship 6.579 683 920 729 e15 0.000 000 000 033 e15 Hz
590hartree-inverse meter relationship 2.194 746 313 708 e7 0.000 000 000 011 e7 m^-1
591hartree-joule relationship 4.359 744 34 e-18 0.000 000 19 e-18 J
592hartree-kelvin relationship 3.157 7504 e5 0.000 0029 e5 K
593hartree-kilogram relationship 4.850 869 79 e-35 0.000 000 21 e-35 kg
594helion-electron mass ratio 5495.885 2754 0.000 0050
595helion g factor -4.255 250 613 0.000 000 050
596helion mag. mom. -1.074 617 486 e-26 0.000 000 027 e-26 J T^-1
597helion mag. mom. to Bohr magneton ratio -1.158 740 958 e-3 0.000 000 014 e-3
598helion mag. mom. to nuclear magneton ratio -2.127 625 306 0.000 000 025
599helion mass 5.006 412 34 e-27 0.000 000 22 e-27 kg
600helion mass energy equivalent 4.499 539 02 e-10 0.000 000 20 e-10 J
601helion mass energy equivalent in MeV 2808.391 482 0.000 062 MeV
602helion mass in u 3.014 932 2468 0.000 000 0025 u
603helion molar mass 3.014 932 2468 e-3 0.000 000 0025 e-3 kg mol^-1
604helion-proton mass ratio 2.993 152 6707 0.000 000 0025
605hertz-atomic mass unit relationship 4.439 821 6689 e-24 0.000 000 0031 e-24 u
606hertz-electron volt relationship 4.135 667 516 e-15 0.000 000 091 e-15 eV
607hertz-hartree relationship 1.519 829 8460045e-16 0.000 000 0000076e-16 E_h
608hertz-inverse meter relationship 3.335 640 951... e-9 (exact) m^-1
609hertz-joule relationship 6.626 069 57 e-34 0.000 000 29 e-34 J
610hertz-kelvin relationship 4.799 2434 e-11 0.000 0044 e-11 K
611hertz-kilogram relationship 7.372 496 68 e-51 0.000 000 33 e-51 kg
612inverse fine-structure constant 137.035 999 074 0.000 000 044
613inverse meter-atomic mass unit relationship 1.331 025 051 20 e-15 0.000 000 000 94 e-15 u
614inverse meter-electron volt relationship 1.239 841 930 e-6 0.000 000 027 e-6 eV
615inverse meter-hartree relationship 4.556 335 252 755 e-8 0.000 000 000 023 e-8 E_h
616inverse meter-hertz relationship 299 792 458 (exact) Hz
617inverse meter-joule relationship 1.986 445 684 e-25 0.000 000 088 e-25 J
618inverse meter-kelvin relationship 1.438 7770 e-2 0.000 0013 e-2 K
619inverse meter-kilogram relationship 2.210 218 902 e-42 0.000 000 098 e-42 kg
620inverse of conductance quantum 12 906.403 7217 0.000 0042 ohm
621Josephson constant 483 597.870 e9 0.011 e9 Hz V^-1
622joule-atomic mass unit relationship 6.700 535 85 e9 0.000 000 30 e9 u
623joule-electron volt relationship 6.241 509 34 e18 0.000 000 14 e18 eV
624joule-hartree relationship 2.293 712 48 e17 0.000 000 10 e17 E_h
625joule-hertz relationship 1.509 190 311 e33 0.000 000 067 e33 Hz
626joule-inverse meter relationship 5.034 117 01 e24 0.000 000 22 e24 m^-1
627joule-kelvin relationship 7.242 9716 e22 0.000 0066 e22 K
628joule-kilogram relationship 1.112 650 056... e-17 (exact) kg
629kelvin-atomic mass unit relationship 9.251 0868 e-14 0.000 0084 e-14 u
630kelvin-electron volt relationship 8.617 3324 e-5 0.000 0078 e-5 eV
631kelvin-hartree relationship 3.166 8114 e-6 0.000 0029 e-6 E_h
632kelvin-hertz relationship 2.083 6618 e10 0.000 0019 e10 Hz
633kelvin-inverse meter relationship 69.503 476 0.000 063 m^-1
634kelvin-joule relationship 1.380 6488 e-23 0.000 0013 e-23 J
635kelvin-kilogram relationship 1.536 1790 e-40 0.000 0014 e-40 kg
636kilogram-atomic mass unit relationship 6.022 141 29 e26 0.000 000 27 e26 u
637kilogram-electron volt relationship 5.609 588 85 e35 0.000 000 12 e35 eV
638kilogram-hartree relationship 2.061 485 968 e34 0.000 000 091 e34 E_h
639kilogram-hertz relationship 1.356 392 608 e50 0.000 000 060 e50 Hz
640kilogram-inverse meter relationship 4.524 438 73 e41 0.000 000 20 e41 m^-1
641kilogram-joule relationship 8.987 551 787... e16 (exact) J
642kilogram-kelvin relationship 6.509 6582 e39 0.000 0059 e39 K
643lattice parameter of silicon 543.102 0504 e-12 0.000 0089 e-12 m
644Loschmidt constant (273.15 K, 100 kPa) 2.651 6462 e25 0.000 0024 e25 m^-3
645Loschmidt constant (273.15 K, 101.325 kPa) 2.686 7805 e25 0.000 0024 e25 m^-3
646mag. constant 12.566 370 614... e-7 (exact) N A^-2
647mag. flux quantum 2.067 833 758 e-15 0.000 000 046 e-15 Wb
648molar gas constant 8.314 4621 0.000 0075 J mol^-1 K^-1
649molar mass constant 1 e-3 (exact) kg mol^-1
650molar mass of carbon-12 12 e-3 (exact) kg mol^-1
651molar Planck constant 3.990 312 7176 e-10 0.000 000 0028 e-10 J s mol^-1
652molar Planck constant times c 0.119 626 565 779 0.000 000 000 084 J m mol^-1
653molar volume of ideal gas (273.15 K, 100 kPa) 22.710 953 e-3 0.000 021 e-3 m^3 mol^-1
654molar volume of ideal gas (273.15 K, 101.325 kPa) 22.413 968 e-3 0.000 020 e-3 m^3 mol^-1
655molar volume of silicon 12.058 833 01 e-6 0.000 000 80 e-6 m^3 mol^-1
656Mo x unit 1.002 099 52 e-13 0.000 000 53 e-13 m
657muon Compton wavelength 11.734 441 03 e-15 0.000 000 30 e-15 m
658muon Compton wavelength over 2 pi 1.867 594 294 e-15 0.000 000 047 e-15 m
659muon-electron mass ratio 206.768 2843 0.000 0052
660muon g factor -2.002 331 8418 0.000 000 0013
661muon mag. mom. -4.490 448 07 e-26 0.000 000 15 e-26 J T^-1
662muon mag. mom. anomaly 1.165 920 91 e-3 0.000 000 63 e-3
663muon mag. mom. to Bohr magneton ratio -4.841 970 44 e-3 0.000 000 12 e-3
664muon mag. mom. to nuclear magneton ratio -8.890 596 97 0.000 000 22
665muon mass 1.883 531 475 e-28 0.000 000 096 e-28 kg
666muon mass energy equivalent 1.692 833 667 e-11 0.000 000 086 e-11 J
667muon mass energy equivalent in MeV 105.658 3715 0.000 0035 MeV
668muon mass in u 0.113 428 9267 0.000 000 0029 u
669muon molar mass 0.113 428 9267 e-3 0.000 000 0029 e-3 kg mol^-1
670muon-neutron mass ratio 0.112 454 5177 0.000 000 0028
671muon-proton mag. mom. ratio -3.183 345 107 0.000 000 084
672muon-proton mass ratio 0.112 609 5272 0.000 000 0028
673muon-tau mass ratio 5.946 49 e-2 0.000 54 e-2
674natural unit of action 1.054 571 726 e-34 0.000 000 047 e-34 J s
675natural unit of action in eV s 6.582 119 28 e-16 0.000 000 15 e-16 eV s
676natural unit of energy 8.187 105 06 e-14 0.000 000 36 e-14 J
677natural unit of energy in MeV 0.510 998 928 0.000 000 011 MeV
678natural unit of length 386.159 268 00 e-15 0.000 000 25 e-15 m
679natural unit of mass 9.109 382 91 e-31 0.000 000 40 e-31 kg
680natural unit of mom.um 2.730 924 29 e-22 0.000 000 12 e-22 kg m s^-1
681natural unit of mom.um in MeV/c 0.510 998 928 0.000 000 011 MeV/c
682natural unit of time 1.288 088 668 33 e-21 0.000 000 000 83 e-21 s
683natural unit of velocity 299 792 458 (exact) m s^-1
684neutron Compton wavelength 1.319 590 9068 e-15 0.000 000 0011 e-15 m
685neutron Compton wavelength over 2 pi 0.210 019 415 68 e-15 0.000 000 000 17 e-15 m
686neutron-electron mag. mom. ratio 1.040 668 82 e-3 0.000 000 25 e-3
687neutron-electron mass ratio 1838.683 6605 0.000 0011
688neutron g factor -3.826 085 45 0.000 000 90
689neutron gyromag. ratio 1.832 471 79 e8 0.000 000 43 e8 s^-1 T^-1
690neutron gyromag. ratio over 2 pi 29.164 6943 0.000 0069 MHz T^-1
691neutron mag. mom. -0.966 236 47 e-26 0.000 000 23 e-26 J T^-1
692neutron mag. mom. to Bohr magneton ratio -1.041 875 63 e-3 0.000 000 25 e-3
693neutron mag. mom. to nuclear magneton ratio -1.913 042 72 0.000 000 45
694neutron mass 1.674 927 351 e-27 0.000 000 074 e-27 kg
695neutron mass energy equivalent 1.505 349 631 e-10 0.000 000 066 e-10 J
696neutron mass energy equivalent in MeV 939.565 379 0.000 021 MeV
697neutron mass in u 1.008 664 916 00 0.000 000 000 43 u
698neutron molar mass 1.008 664 916 00 e-3 0.000 000 000 43 e-3 kg mol^-1
699neutron-muon mass ratio 8.892 484 00 0.000 000 22
700neutron-proton mag. mom. ratio -0.684 979 34 0.000 000 16
701neutron-proton mass difference 2.305 573 92 e-30 0.000 000 76 e-30
702neutron-proton mass difference energy equivalent 2.072 146 50 e-13 0.000 000 68 e-13
703neutron-proton mass difference energy equivalent in MeV 1.293 332 17 0.000 000 42
704neutron-proton mass difference in u 0.001 388 449 19 0.000 000 000 45
705neutron-proton mass ratio 1.001 378 419 17 0.000 000 000 45
706neutron-tau mass ratio 0.528 790 0.000 048
707neutron to shielded proton mag. mom. ratio -0.684 996 94 0.000 000 16
708Newtonian constant of gravitation 6.673 84 e-11 0.000 80 e-11 m^3 kg^-1 s^-2
709Newtonian constant of gravitation over h-bar c 6.708 37 e-39 0.000 80 e-39 (GeV/c^2)^-2
710nuclear magneton 5.050 783 53 e-27 0.000 000 11 e-27 J T^-1
711nuclear magneton in eV/T 3.152 451 2605 e-8 0.000 000 0022 e-8 eV T^-1
712nuclear magneton in inverse meters per tesla 2.542 623 527 e-2 0.000 000 056 e-2 m^-1 T^-1
713nuclear magneton in K/T 3.658 2682 e-4 0.000 0033 e-4 K T^-1
714nuclear magneton in MHz/T 7.622 593 57 0.000 000 17 MHz T^-1
715Planck constant 6.626 069 57 e-34 0.000 000 29 e-34 J s
716Planck constant in eV s 4.135 667 516 e-15 0.000 000 091 e-15 eV s
717Planck constant over 2 pi 1.054 571 726 e-34 0.000 000 047 e-34 J s
718Planck constant over 2 pi in eV s 6.582 119 28 e-16 0.000 000 15 e-16 eV s
719Planck constant over 2 pi times c in MeV fm 197.326 9718 0.000 0044 MeV fm
720Planck length 1.616 199 e-35 0.000 097 e-35 m
721Planck mass 2.176 51 e-8 0.000 13 e-8 kg
722Planck mass energy equivalent in GeV 1.220 932 e19 0.000 073 e19 GeV
723Planck temperature 1.416 833 e32 0.000 085 e32 K
724Planck time 5.391 06 e-44 0.000 32 e-44 s
725proton charge to mass quotient 9.578 833 58 e7 0.000 000 21 e7 C kg^-1
726proton Compton wavelength 1.321 409 856 23 e-15 0.000 000 000 94 e-15 m
727proton Compton wavelength over 2 pi 0.210 308 910 47 e-15 0.000 000 000 15 e-15 m
728proton-electron mass ratio 1836.152 672 45 0.000 000 75
729proton g factor 5.585 694 713 0.000 000 046
730proton gyromag. ratio 2.675 222 005 e8 0.000 000 063 e8 s^-1 T^-1
731proton gyromag. ratio over 2 pi 42.577 4806 0.000 0010 MHz T^-1
732proton mag. mom. 1.410 606 743 e-26 0.000 000 033 e-26 J T^-1
733proton mag. mom. to Bohr magneton ratio 1.521 032 210 e-3 0.000 000 012 e-3
734proton mag. mom. to nuclear magneton ratio 2.792 847 356 0.000 000 023
735proton mag. shielding correction 25.694 e-6 0.014 e-6
736proton mass 1.672 621 777 e-27 0.000 000 074 e-27 kg
737proton mass energy equivalent 1.503 277 484 e-10 0.000 000 066 e-10 J
738proton mass energy equivalent in MeV 938.272 046 0.000 021 MeV
739proton mass in u 1.007 276 466 812 0.000 000 000 090 u
740proton molar mass 1.007 276 466 812 e-3 0.000 000 000 090 e-3 kg mol^-1
741proton-muon mass ratio 8.880 243 31 0.000 000 22
742proton-neutron mag. mom. ratio -1.459 898 06 0.000 000 34
743proton-neutron mass ratio 0.998 623 478 26 0.000 000 000 45
744proton rms charge radius 0.8775 e-15 0.0051 e-15 m
745proton-tau mass ratio 0.528 063 0.000 048
746quantum of circulation 3.636 947 5520 e-4 0.000 000 0024 e-4 m^2 s^-1
747quantum of circulation times 2 7.273 895 1040 e-4 0.000 000 0047 e-4 m^2 s^-1
748Rydberg constant 10 973 731.568 539 0.000 055 m^-1
749Rydberg constant times c in Hz 3.289 841 960 364 e15 0.000 000 000 017 e15 Hz
750Rydberg constant times hc in eV 13.605 692 53 0.000 000 30 eV
751Rydberg constant times hc in J 2.179 872 171 e-18 0.000 000 096 e-18 J
752Sackur-Tetrode constant (1 K, 100 kPa) -1.151 7078 0.000 0023
753Sackur-Tetrode constant (1 K, 101.325 kPa) -1.164 8708 0.000 0023
754second radiation constant 1.438 7770 e-2 0.000 0013 e-2 m K
755shielded helion gyromag. ratio 2.037 894 659 e8 0.000 000 051 e8 s^-1 T^-1
756shielded helion gyromag. ratio over 2 pi 32.434 100 84 0.000 000 81 MHz T^-1
757shielded helion mag. mom. -1.074 553 044 e-26 0.000 000 027 e-26 J T^-1
758shielded helion mag. mom. to Bohr magneton ratio -1.158 671 471 e-3 0.000 000 014 e-3
759shielded helion mag. mom. to nuclear magneton ratio -2.127 497 718 0.000 000 025
760shielded helion to proton mag. mom. ratio -0.761 766 558 0.000 000 011
761shielded helion to shielded proton mag. mom. ratio -0.761 786 1313 0.000 000 0033
762shielded proton gyromag. ratio 2.675 153 268 e8 0.000 000 066 e8 s^-1 T^-1
763shielded proton gyromag. ratio over 2 pi 42.576 3866 0.000 0010 MHz T^-1
764shielded proton mag. mom. 1.410 570 499 e-26 0.000 000 035 e-26 J T^-1
765shielded proton mag. mom. to Bohr magneton ratio 1.520 993 128 e-3 0.000 000 017 e-3
766shielded proton mag. mom. to nuclear magneton ratio 2.792 775 598 0.000 000 030
767speed of light in vacuum 299 792 458 (exact) m s^-1
768standard acceleration of gravity 9.806 65 (exact) m s^-2
769standard atmosphere 101 325 (exact) Pa
770standard-state pressure 100 000 (exact) Pa
771Stefan-Boltzmann constant 5.670 373 e-8 0.000 021 e-8 W m^-2 K^-4
772tau Compton wavelength 0.697 787 e-15 0.000 063 e-15 m
773tau Compton wavelength over 2 pi 0.111 056 e-15 0.000 010 e-15 m
774tau-electron mass ratio 3477.15 0.31
775tau mass 3.167 47 e-27 0.000 29 e-27 kg
776tau mass energy equivalent 2.846 78 e-10 0.000 26 e-10 J
777tau mass energy equivalent in MeV 1776.82 0.16 MeV
778tau mass in u 1.907 49 0.000 17 u
779tau molar mass 1.907 49 e-3 0.000 17 e-3 kg mol^-1
780tau-muon mass ratio 16.8167 0.0015
781tau-neutron mass ratio 1.891 11 0.000 17
782tau-proton mass ratio 1.893 72 0.000 17
783Thomson cross section 0.665 245 8734 e-28 0.000 000 0013 e-28 m^2
784triton-electron mass ratio 5496.921 5267 0.000 0050
785triton g factor 5.957 924 896 0.000 000 076
786triton mag. mom. 1.504 609 447 e-26 0.000 000 038 e-26 J T^-1
787triton mag. mom. to Bohr magneton ratio 1.622 393 657 e-3 0.000 000 021 e-3
788triton mag. mom. to nuclear magneton ratio 2.978 962 448 0.000 000 038
789triton mass 5.007 356 30 e-27 0.000 000 22 e-27 kg
790triton mass energy equivalent 4.500 387 41 e-10 0.000 000 20 e-10 J
791triton mass energy equivalent in MeV 2808.921 005 0.000 062 MeV
792triton mass in u 3.015 500 7134 0.000 000 0025 u
793triton molar mass 3.015 500 7134 e-3 0.000 000 0025 e-3 kg mol^-1
794triton-proton mass ratio 2.993 717 0308 0.000 000 0025
795unified atomic mass unit 1.660 538 921 e-27 0.000 000 073 e-27 kg
796von Klitzing constant 25 812.807 4434 0.000 0084 ohm
797weak mixing angle 0.2223 0.0021
798Wien frequency displacement law constant 5.878 9254 e10 0.000 0053 e10 Hz K^-1
799Wien wavelength displacement law constant 2.897 7721 e-3 0.000 0026 e-3 m K"""
801txt2014 = """\
802{220} lattice spacing of silicon 192.015 5714 e-12 0.000 0032 e-12 m
803alpha particle-electron mass ratio 7294.299 541 36 0.000 000 24
804alpha particle mass 6.644 657 230 e-27 0.000 000 082 e-27 kg
805alpha particle mass energy equivalent 5.971 920 097 e-10 0.000 000 073 e-10 J
806alpha particle mass energy equivalent in MeV 3727.379 378 0.000 023 MeV
807alpha particle mass in u 4.001 506 179 127 0.000 000 000 063 u
808alpha particle molar mass 4.001 506 179 127 e-3 0.000 000 000 063 e-3 kg mol^-1
809alpha particle-proton mass ratio 3.972 599 689 07 0.000 000 000 36
810Angstrom star 1.000 014 95 e-10 0.000 000 90 e-10 m
811atomic mass constant 1.660 539 040 e-27 0.000 000 020 e-27 kg
812atomic mass constant energy equivalent 1.492 418 062 e-10 0.000 000 018 e-10 J
813atomic mass constant energy equivalent in MeV 931.494 0954 0.000 0057 MeV
814atomic mass unit-electron volt relationship 931.494 0954 e6 0.000 0057 e6 eV
815atomic mass unit-hartree relationship 3.423 177 6902 e7 0.000 000 0016 e7 E_h
816atomic mass unit-hertz relationship 2.252 342 7206 e23 0.000 000 0010 e23 Hz
817atomic mass unit-inverse meter relationship 7.513 006 6166 e14 0.000 000 0034 e14 m^-1
818atomic mass unit-joule relationship 1.492 418 062 e-10 0.000 000 018 e-10 J
819atomic mass unit-kelvin relationship 1.080 954 38 e13 0.000 000 62 e13 K
820atomic mass unit-kilogram relationship 1.660 539 040 e-27 0.000 000 020 e-27 kg
821atomic unit of 1st hyperpolarizability 3.206 361 329 e-53 0.000 000 020 e-53 C^3 m^3 J^-2
822atomic unit of 2nd hyperpolarizability 6.235 380 085 e-65 0.000 000 077 e-65 C^4 m^4 J^-3
823atomic unit of action 1.054 571 800 e-34 0.000 000 013 e-34 J s
824atomic unit of charge 1.602 176 6208 e-19 0.000 000 0098 e-19 C
825atomic unit of charge density 1.081 202 3770 e12 0.000 000 0067 e12 C m^-3
826atomic unit of current 6.623 618 183 e-3 0.000 000 041 e-3 A
827atomic unit of electric dipole mom. 8.478 353 552 e-30 0.000 000 052 e-30 C m
828atomic unit of electric field 5.142 206 707 e11 0.000 000 032 e11 V m^-1
829atomic unit of electric field gradient 9.717 362 356 e21 0.000 000 060 e21 V m^-2
830atomic unit of electric polarizability 1.648 777 2731 e-41 0.000 000 0011 e-41 C^2 m^2 J^-1
831atomic unit of electric potential 27.211 386 02 0.000 000 17 V
832atomic unit of electric quadrupole mom. 4.486 551 484 e-40 0.000 000 028 e-40 C m^2
833atomic unit of energy 4.359 744 650 e-18 0.000 000 054 e-18 J
834atomic unit of force 8.238 723 36 e-8 0.000 000 10 e-8 N
835atomic unit of length 0.529 177 210 67 e-10 0.000 000 000 12 e-10 m
836atomic unit of mag. dipole mom. 1.854 801 999 e-23 0.000 000 011 e-23 J T^-1
837atomic unit of mag. flux density 2.350 517 550 e5 0.000 000 014 e5 T
838atomic unit of magnetizability 7.891 036 5886 e-29 0.000 000 0090 e-29 J T^-2
839atomic unit of mass 9.109 383 56 e-31 0.000 000 11 e-31 kg
840atomic unit of mom.um 1.992 851 882 e-24 0.000 000 024 e-24 kg m s^-1
841atomic unit of permittivity 1.112 650 056... e-10 (exact) F m^-1
842atomic unit of time 2.418 884 326509e-17 0.000 000 000014e-17 s
843atomic unit of velocity 2.187 691 262 77 e6 0.000 000 000 50 e6 m s^-1
844Avogadro constant 6.022 140 857 e23 0.000 000 074 e23 mol^-1
845Bohr magneton 927.400 9994 e-26 0.000 0057 e-26 J T^-1
846Bohr magneton in eV/T 5.788 381 8012 e-5 0.000 000 0026 e-5 eV T^-1
847Bohr magneton in Hz/T 13.996 245 042 e9 0.000 000 086 e9 Hz T^-1
848Bohr magneton in inverse meters per tesla 46.686 448 14 0.000 000 29 m^-1 T^-1
849Bohr magneton in K/T 0.671 714 05 0.000 000 39 K T^-1
850Bohr radius 0.529 177 210 67 e-10 0.000 000 000 12 e-10 m
851Boltzmann constant 1.380 648 52 e-23 0.000 000 79 e-23 J K^-1
852Boltzmann constant in eV/K 8.617 3303 e-5 0.000 0050 e-5 eV K^-1
853Boltzmann constant in Hz/K 2.083 6612 e10 0.000 0012 e10 Hz K^-1
854Boltzmann constant in inverse meters per kelvin 69.503 457 0.000 040 m^-1 K^-1
855characteristic impedance of vacuum 376.730 313 461... (exact) ohm
856classical electron radius 2.817 940 3227 e-15 0.000 000 0019 e-15 m
857Compton wavelength 2.426 310 2367 e-12 0.000 000 0011 e-12 m
858Compton wavelength over 2 pi 386.159 267 64 e-15 0.000 000 18 e-15 m
859conductance quantum 7.748 091 7310 e-5 0.000 000 0018 e-5 S
860conventional value of Josephson constant 483 597.9 e9 (exact) Hz V^-1
861conventional value of von Klitzing constant 25 812.807 (exact) ohm
862Cu x unit 1.002 076 97 e-13 0.000 000 28 e-13 m
863deuteron-electron mag. mom. ratio -4.664 345 535 e-4 0.000 000 026 e-4
864deuteron-electron mass ratio 3670.482 967 85 0.000 000 13
865deuteron g factor 0.857 438 2311 0.000 000 0048
866deuteron mag. mom. 0.433 073 5040 e-26 0.000 000 0036 e-26 J T^-1
867deuteron mag. mom. to Bohr magneton ratio 0.466 975 4554 e-3 0.000 000 0026 e-3
868deuteron mag. mom. to nuclear magneton ratio 0.857 438 2311 0.000 000 0048
869deuteron mass 3.343 583 719 e-27 0.000 000 041 e-27 kg
870deuteron mass energy equivalent 3.005 063 183 e-10 0.000 000 037 e-10 J
871deuteron mass energy equivalent in MeV 1875.612 928 0.000 012 MeV
872deuteron mass in u 2.013 553 212 745 0.000 000 000 040 u
873deuteron molar mass 2.013 553 212 745 e-3 0.000 000 000 040 e-3 kg mol^-1
874deuteron-neutron mag. mom. ratio -0.448 206 52 0.000 000 11
875deuteron-proton mag. mom. ratio 0.307 012 2077 0.000 000 0015
876deuteron-proton mass ratio 1.999 007 500 87 0.000 000 000 19
877deuteron rms charge radius 2.1413 e-15 0.0025 e-15 m
878electric constant 8.854 187 817... e-12 (exact) F m^-1
879electron charge to mass quotient -1.758 820 024 e11 0.000 000 011 e11 C kg^-1
880electron-deuteron mag. mom. ratio -2143.923 499 0.000 012
881electron-deuteron mass ratio 2.724 437 107 484 e-4 0.000 000 000 096 e-4
882electron g factor -2.002 319 304 361 82 0.000 000 000 000 52
883electron gyromag. ratio 1.760 859 644 e11 0.000 000 011 e11 s^-1 T^-1
884electron gyromag. ratio over 2 pi 28 024.951 64 0.000 17 MHz T^-1
885electron-helion mass ratio 1.819 543 074 854 e-4 0.000 000 000 088 e-4
886electron mag. mom. -928.476 4620 e-26 0.000 0057 e-26 J T^-1
887electron mag. mom. anomaly 1.159 652 180 91 e-3 0.000 000 000 26 e-3
888electron mag. mom. to Bohr magneton ratio -1.001 159 652 180 91 0.000 000 000 000 26
889electron mag. mom. to nuclear magneton ratio -1838.281 972 34 0.000 000 17
890electron mass 9.109 383 56 e-31 0.000 000 11 e-31 kg
891electron mass energy equivalent 8.187 105 65 e-14 0.000 000 10 e-14 J
892electron mass energy equivalent in MeV 0.510 998 9461 0.000 000 0031 MeV
893electron mass in u 5.485 799 090 70 e-4 0.000 000 000 16 e-4 u
894electron molar mass 5.485 799 090 70 e-7 0.000 000 000 16 e-7 kg mol^-1
895electron-muon mag. mom. ratio 206.766 9880 0.000 0046
896electron-muon mass ratio 4.836 331 70 e-3 0.000 000 11 e-3
897electron-neutron mag. mom. ratio 960.920 50 0.000 23
898electron-neutron mass ratio 5.438 673 4428 e-4 0.000 000 0027 e-4
899electron-proton mag. mom. ratio -658.210 6866 0.000 0020
900electron-proton mass ratio 5.446 170 213 52 e-4 0.000 000 000 52 e-4
901electron-tau mass ratio 2.875 92 e-4 0.000 26 e-4
902electron to alpha particle mass ratio 1.370 933 554 798 e-4 0.000 000 000 045 e-4
903electron to shielded helion mag. mom. ratio 864.058 257 0.000 010
904electron to shielded proton mag. mom. ratio -658.227 5971 0.000 0072
905electron-triton mass ratio 1.819 200 062 203 e-4 0.000 000 000 084 e-4
906electron volt 1.602 176 6208 e-19 0.000 000 0098 e-19 J
907electron volt-atomic mass unit relationship 1.073 544 1105 e-9 0.000 000 0066 e-9 u
908electron volt-hartree relationship 3.674 932 248 e-2 0.000 000 023 e-2 E_h
909electron volt-hertz relationship 2.417 989 262 e14 0.000 000 015 e14 Hz
910electron volt-inverse meter relationship 8.065 544 005 e5 0.000 000 050 e5 m^-1
911electron volt-joule relationship 1.602 176 6208 e-19 0.000 000 0098 e-19 J
912electron volt-kelvin relationship 1.160 452 21 e4 0.000 000 67 e4 K
913electron volt-kilogram relationship 1.782 661 907 e-36 0.000 000 011 e-36 kg
914elementary charge 1.602 176 6208 e-19 0.000 000 0098 e-19 C
915elementary charge over h 2.417 989 262 e14 0.000 000 015 e14 A J^-1
916Faraday constant 96 485.332 89 0.000 59 C mol^-1
917Faraday constant for conventional electric current 96 485.3251 0.0012 C_90 mol^-1
918Fermi coupling constant 1.166 3787 e-5 0.000 0006 e-5 GeV^-2
919fine-structure constant 7.297 352 5664 e-3 0.000 000 0017 e-3
920first radiation constant 3.741 771 790 e-16 0.000 000 046 e-16 W m^2
921first radiation constant for spectral radiance 1.191 042 953 e-16 0.000 000 015 e-16 W m^2 sr^-1
922hartree-atomic mass unit relationship 2.921 262 3197 e-8 0.000 000 0013 e-8 u
923hartree-electron volt relationship 27.211 386 02 0.000 000 17 eV
924Hartree energy 4.359 744 650 e-18 0.000 000 054 e-18 J
925Hartree energy in eV 27.211 386 02 0.000 000 17 eV
926hartree-hertz relationship 6.579 683 920 711 e15 0.000 000 000 039 e15 Hz
927hartree-inverse meter relationship 2.194 746 313 702 e7 0.000 000 000 013 e7 m^-1
928hartree-joule relationship 4.359 744 650 e-18 0.000 000 054 e-18 J
929hartree-kelvin relationship 3.157 7513 e5 0.000 0018 e5 K
930hartree-kilogram relationship 4.850 870 129 e-35 0.000 000 060 e-35 kg
931helion-electron mass ratio 5495.885 279 22 0.000 000 27
932helion g factor -4.255 250 616 0.000 000 050
933helion mag. mom. -1.074 617 522 e-26 0.000 000 014 e-26 J T^-1
934helion mag. mom. to Bohr magneton ratio -1.158 740 958 e-3 0.000 000 014 e-3
935helion mag. mom. to nuclear magneton ratio -2.127 625 308 0.000 000 025
936helion mass 5.006 412 700 e-27 0.000 000 062 e-27 kg
937helion mass energy equivalent 4.499 539 341 e-10 0.000 000 055 e-10 J
938helion mass energy equivalent in MeV 2808.391 586 0.000 017 MeV
939helion mass in u 3.014 932 246 73 0.000 000 000 12 u
940helion molar mass 3.014 932 246 73 e-3 0.000 000 000 12 e-3 kg mol^-1
941helion-proton mass ratio 2.993 152 670 46 0.000 000 000 29
942hertz-atomic mass unit relationship 4.439 821 6616 e-24 0.000 000 0020 e-24 u
943hertz-electron volt relationship 4.135 667 662 e-15 0.000 000 025 e-15 eV
944hertz-hartree relationship 1.5198298460088 e-16 0.0000000000090e-16 E_h
945hertz-inverse meter relationship 3.335 640 951... e-9 (exact) m^-1
946hertz-joule relationship 6.626 070 040 e-34 0.000 000 081 e-34 J
947hertz-kelvin relationship 4.799 2447 e-11 0.000 0028 e-11 K
948hertz-kilogram relationship 7.372 497 201 e-51 0.000 000 091 e-51 kg
949inverse fine-structure constant 137.035 999 139 0.000 000 031
950inverse meter-atomic mass unit relationship 1.331 025 049 00 e-15 0.000 000 000 61 e-15 u
951inverse meter-electron volt relationship 1.239 841 9739 e-6 0.000 000 0076 e-6 eV
952inverse meter-hartree relationship 4.556 335 252 767 e-8 0.000 000 000 027 e-8 E_h
953inverse meter-hertz relationship 299 792 458 (exact) Hz
954inverse meter-joule relationship 1.986 445 824 e-25 0.000 000 024 e-25 J
955inverse meter-kelvin relationship 1.438 777 36 e-2 0.000 000 83 e-2 K
956inverse meter-kilogram relationship 2.210 219 057 e-42 0.000 000 027 e-42 kg
957inverse of conductance quantum 12 906.403 7278 0.000 0029 ohm
958Josephson constant 483 597.8525 e9 0.0030 e9 Hz V^-1
959joule-atomic mass unit relationship 6.700 535 363 e9 0.000 000 082 e9 u
960joule-electron volt relationship 6.241 509 126 e18 0.000 000 038 e18 eV
961joule-hartree relationship 2.293 712 317 e17 0.000 000 028 e17 E_h
962joule-hertz relationship 1.509 190 205 e33 0.000 000 019 e33 Hz
963joule-inverse meter relationship 5.034 116 651 e24 0.000 000 062 e24 m^-1
964joule-kelvin relationship 7.242 9731 e22 0.000 0042 e22 K
965joule-kilogram relationship 1.112 650 056... e-17 (exact) kg
966kelvin-atomic mass unit relationship 9.251 0842 e-14 0.000 0053 e-14 u
967kelvin-electron volt relationship 8.617 3303 e-5 0.000 0050 e-5 eV
968kelvin-hartree relationship 3.166 8105 e-6 0.000 0018 e-6 E_h
969kelvin-hertz relationship 2.083 6612 e10 0.000 0012 e10 Hz
970kelvin-inverse meter relationship 69.503 457 0.000 040 m^-1
971kelvin-joule relationship 1.380 648 52 e-23 0.000 000 79 e-23 J
972kelvin-kilogram relationship 1.536 178 65 e-40 0.000 000 88 e-40 kg
973kilogram-atomic mass unit relationship 6.022 140 857 e26 0.000 000 074 e26 u
974kilogram-electron volt relationship 5.609 588 650 e35 0.000 000 034 e35 eV
975kilogram-hartree relationship 2.061 485 823 e34 0.000 000 025 e34 E_h
976kilogram-hertz relationship 1.356 392 512 e50 0.000 000 017 e50 Hz
977kilogram-inverse meter relationship 4.524 438 411 e41 0.000 000 056 e41 m^-1
978kilogram-joule relationship 8.987 551 787... e16 (exact) J
979kilogram-kelvin relationship 6.509 6595 e39 0.000 0037 e39 K
980lattice parameter of silicon 543.102 0504 e-12 0.000 0089 e-12 m
981Loschmidt constant (273.15 K, 100 kPa) 2.651 6467 e25 0.000 0015 e25 m^-3
982Loschmidt constant (273.15 K, 101.325 kPa) 2.686 7811 e25 0.000 0015 e25 m^-3
983mag. constant 12.566 370 614... e-7 (exact) N A^-2
984mag. flux quantum 2.067 833 831 e-15 0.000 000 013 e-15 Wb
985molar gas constant 8.314 4598 0.000 0048 J mol^-1 K^-1
986molar mass constant 1 e-3 (exact) kg mol^-1
987molar mass of carbon-12 12 e-3 (exact) kg mol^-1
988molar Planck constant 3.990 312 7110 e-10 0.000 000 0018 e-10 J s mol^-1
989molar Planck constant times c 0.119 626 565 582 0.000 000 000 054 J m mol^-1
990molar volume of ideal gas (273.15 K, 100 kPa) 22.710 947 e-3 0.000 013 e-3 m^3 mol^-1
991molar volume of ideal gas (273.15 K, 101.325 kPa) 22.413 962 e-3 0.000 013 e-3 m^3 mol^-1
992molar volume of silicon 12.058 832 14 e-6 0.000 000 61 e-6 m^3 mol^-1
993Mo x unit 1.002 099 52 e-13 0.000 000 53 e-13 m
994muon Compton wavelength 11.734 441 11 e-15 0.000 000 26 e-15 m
995muon Compton wavelength over 2 pi 1.867 594 308 e-15 0.000 000 042 e-15 m
996muon-electron mass ratio 206.768 2826 0.000 0046
997muon g factor -2.002 331 8418 0.000 000 0013
998muon mag. mom. -4.490 448 26 e-26 0.000 000 10 e-26 J T^-1
999muon mag. mom. anomaly 1.165 920 89 e-3 0.000 000 63 e-3
1000muon mag. mom. to Bohr magneton ratio -4.841 970 48 e-3 0.000 000 11 e-3
1001muon mag. mom. to nuclear magneton ratio -8.890 597 05 0.000 000 20
1002muon mass 1.883 531 594 e-28 0.000 000 048 e-28 kg
1003muon mass energy equivalent 1.692 833 774 e-11 0.000 000 043 e-11 J
1004muon mass energy equivalent in MeV 105.658 3745 0.000 0024 MeV
1005muon mass in u 0.113 428 9257 0.000 000 0025 u
1006muon molar mass 0.113 428 9257 e-3 0.000 000 0025 e-3 kg mol^-1
1007muon-neutron mass ratio 0.112 454 5167 0.000 000 0025
1008muon-proton mag. mom. ratio -3.183 345 142 0.000 000 071
1009muon-proton mass ratio 0.112 609 5262 0.000 000 0025
1010muon-tau mass ratio 5.946 49 e-2 0.000 54 e-2
1011natural unit of action 1.054 571 800 e-34 0.000 000 013 e-34 J s
1012natural unit of action in eV s 6.582 119 514 e-16 0.000 000 040 e-16 eV s
1013natural unit of energy 8.187 105 65 e-14 0.000 000 10 e-14 J
1014natural unit of energy in MeV 0.510 998 9461 0.000 000 0031 MeV
1015natural unit of length 386.159 267 64 e-15 0.000 000 18 e-15 m
1016natural unit of mass 9.109 383 56 e-31 0.000 000 11 e-31 kg
1017natural unit of mom.um 2.730 924 488 e-22 0.000 000 034 e-22 kg m s^-1
1018natural unit of mom.um in MeV/c 0.510 998 9461 0.000 000 0031 MeV/c
1019natural unit of time 1.288 088 667 12 e-21 0.000 000 000 58 e-21 s
1020natural unit of velocity 299 792 458 (exact) m s^-1
1021neutron Compton wavelength 1.319 590 904 81 e-15 0.000 000 000 88 e-15 m
1022neutron Compton wavelength over 2 pi 0.210 019 415 36 e-15 0.000 000 000 14 e-15 m
1023neutron-electron mag. mom. ratio 1.040 668 82 e-3 0.000 000 25 e-3
1024neutron-electron mass ratio 1838.683 661 58 0.000 000 90
1025neutron g factor -3.826 085 45 0.000 000 90
1026neutron gyromag. ratio 1.832 471 72 e8 0.000 000 43 e8 s^-1 T^-1
1027neutron gyromag. ratio over 2 pi 29.164 6933 0.000 0069 MHz T^-1
1028neutron mag. mom. -0.966 236 50 e-26 0.000 000 23 e-26 J T^-1
1029neutron mag. mom. to Bohr magneton ratio -1.041 875 63 e-3 0.000 000 25 e-3
1030neutron mag. mom. to nuclear magneton ratio -1.913 042 73 0.000 000 45
1031neutron mass 1.674 927 471 e-27 0.000 000 021 e-27 kg
1032neutron mass energy equivalent 1.505 349 739 e-10 0.000 000 019 e-10 J
1033neutron mass energy equivalent in MeV 939.565 4133 0.000 0058 MeV
1034neutron mass in u 1.008 664 915 88 0.000 000 000 49 u
1035neutron molar mass 1.008 664 915 88 e-3 0.000 000 000 49 e-3 kg mol^-1
1036neutron-muon mass ratio 8.892 484 08 0.000 000 20
1037neutron-proton mag. mom. ratio -0.684 979 34 0.000 000 16
1038neutron-proton mass difference 2.305 573 77 e-30 0.000 000 85 e-30
1039neutron-proton mass difference energy equivalent 2.072 146 37 e-13 0.000 000 76 e-13
1040neutron-proton mass difference energy equivalent in MeV 1.293 332 05 0.000 000 48
1041neutron-proton mass difference in u 0.001 388 449 00 0.000 000 000 51
1042neutron-proton mass ratio 1.001 378 418 98 0.000 000 000 51
1043neutron-tau mass ratio 0.528 790 0.000 048
1044neutron to shielded proton mag. mom. ratio -0.684 996 94 0.000 000 16
1045Newtonian constant of gravitation 6.674 08 e-11 0.000 31 e-11 m^3 kg^-1 s^-2
1046Newtonian constant of gravitation over h-bar c 6.708 61 e-39 0.000 31 e-39 (GeV/c^2)^-2
1047nuclear magneton 5.050 783 699 e-27 0.000 000 031 e-27 J T^-1
1048nuclear magneton in eV/T 3.152 451 2550 e-8 0.000 000 0015 e-8 eV T^-1
1049nuclear magneton in inverse meters per tesla 2.542 623 432 e-2 0.000 000 016 e-2 m^-1 T^-1
1050nuclear magneton in K/T 3.658 2690 e-4 0.000 0021 e-4 K T^-1
1051nuclear magneton in MHz/T 7.622 593 285 0.000 000 047 MHz T^-1
1052Planck constant 6.626 070 040 e-34 0.000 000 081 e-34 J s
1053Planck constant in eV s 4.135 667 662 e-15 0.000 000 025 e-15 eV s
1054Planck constant over 2 pi 1.054 571 800 e-34 0.000 000 013 e-34 J s
1055Planck constant over 2 pi in eV s 6.582 119 514 e-16 0.000 000 040 e-16 eV s
1056Planck constant over 2 pi times c in MeV fm 197.326 9788 0.000 0012 MeV fm
1057Planck length 1.616 229 e-35 0.000 038 e-35 m
1058Planck mass 2.176 470 e-8 0.000 051 e-8 kg
1059Planck mass energy equivalent in GeV 1.220 910 e19 0.000 029 e19 GeV
1060Planck temperature 1.416 808 e32 0.000 033 e32 K
1061Planck time 5.391 16 e-44 0.000 13 e-44 s
1062proton charge to mass quotient 9.578 833 226 e7 0.000 000 059 e7 C kg^-1
1063proton Compton wavelength 1.321 409 853 96 e-15 0.000 000 000 61 e-15 m
1064proton Compton wavelength over 2 pi 0.210 308910109e-15 0.000 000 000097e-15 m
1065proton-electron mass ratio 1836.152 673 89 0.000 000 17
1066proton g factor 5.585 694 702 0.000 000 017
1067proton gyromag. ratio 2.675 221 900 e8 0.000 000 018 e8 s^-1 T^-1
1068proton gyromag. ratio over 2 pi 42.577 478 92 0.000 000 29 MHz T^-1
1069proton mag. mom. 1.410 606 7873 e-26 0.000 000 0097 e-26 J T^-1
1070proton mag. mom. to Bohr magneton ratio 1.521 032 2053 e-3 0.000 000 0046 e-3
1071proton mag. mom. to nuclear magneton ratio 2.792 847 3508 0.000 000 0085
1072proton mag. shielding correction 25.691 e-6 0.011 e-6
1073proton mass 1.672 621 898 e-27 0.000 000 021 e-27 kg
1074proton mass energy equivalent 1.503 277 593 e-10 0.000 000 018 e-10 J
1075proton mass energy equivalent in MeV 938.272 0813 0.000 0058 MeV
1076proton mass in u 1.007 276 466 879 0.000 000 000 091 u
1077proton molar mass 1.007 276 466 879 e-3 0.000 000 000 091 e-3 kg mol^-1
1078proton-muon mass ratio 8.880 243 38 0.000 000 20
1079proton-neutron mag. mom. ratio -1.459 898 05 0.000 000 34
1080proton-neutron mass ratio 0.998 623 478 44 0.000 000 000 51
1081proton rms charge radius 0.8751 e-15 0.0061 e-15 m
1082proton-tau mass ratio 0.528 063 0.000 048
1083quantum of circulation 3.636 947 5486 e-4 0.000 000 0017 e-4 m^2 s^-1
1084quantum of circulation times 2 7.273 895 0972 e-4 0.000 000 0033 e-4 m^2 s^-1
1085Rydberg constant 10 973 731.568 508 0.000 065 m^-1
1086Rydberg constant times c in Hz 3.289 841 960 355 e15 0.000 000 000 019 e15 Hz
1087Rydberg constant times hc in eV 13.605 693 009 0.000 000 084 eV
1088Rydberg constant times hc in J 2.179 872 325 e-18 0.000 000 027 e-18 J
1089Sackur-Tetrode constant (1 K, 100 kPa) -1.151 7084 0.000 0014
1090Sackur-Tetrode constant (1 K, 101.325 kPa) -1.164 8714 0.000 0014
1091second radiation constant 1.438 777 36 e-2 0.000 000 83 e-2 m K
1092shielded helion gyromag. ratio 2.037 894 585 e8 0.000 000 027 e8 s^-1 T^-1
1093shielded helion gyromag. ratio over 2 pi 32.434 099 66 0.000 000 43 MHz T^-1
1094shielded helion mag. mom. -1.074 553 080 e-26 0.000 000 014 e-26 J T^-1
1095shielded helion mag. mom. to Bohr magneton ratio -1.158 671 471 e-3 0.000 000 014 e-3
1096shielded helion mag. mom. to nuclear magneton ratio -2.127 497 720 0.000 000 025
1097shielded helion to proton mag. mom. ratio -0.761 766 5603 0.000 000 0092
1098shielded helion to shielded proton mag. mom. ratio -0.761 786 1313 0.000 000 0033
1099shielded proton gyromag. ratio 2.675 153 171 e8 0.000 000 033 e8 s^-1 T^-1
1100shielded proton gyromag. ratio over 2 pi 42.576 385 07 0.000 000 53 MHz T^-1
1101shielded proton mag. mom. 1.410 570 547 e-26 0.000 000 018 e-26 J T^-1
1102shielded proton mag. mom. to Bohr magneton ratio 1.520 993 128 e-3 0.000 000 017 e-3
1103shielded proton mag. mom. to nuclear magneton ratio 2.792 775 600 0.000 000 030
1104speed of light in vacuum 299 792 458 (exact) m s^-1
1105standard acceleration of gravity 9.806 65 (exact) m s^-2
1106standard atmosphere 101 325 (exact) Pa
1107standard-state pressure 100 000 (exact) Pa
1108Stefan-Boltzmann constant 5.670 367 e-8 0.000 013 e-8 W m^-2 K^-4
1109tau Compton wavelength 0.697 787 e-15 0.000 063 e-15 m
1110tau Compton wavelength over 2 pi 0.111 056 e-15 0.000 010 e-15 m
1111tau-electron mass ratio 3477.15 0.31
1112tau mass 3.167 47 e-27 0.000 29 e-27 kg
1113tau mass energy equivalent 2.846 78 e-10 0.000 26 e-10 J
1114tau mass energy equivalent in MeV 1776.82 0.16 MeV
1115tau mass in u 1.907 49 0.000 17 u
1116tau molar mass 1.907 49 e-3 0.000 17 e-3 kg mol^-1
1117tau-muon mass ratio 16.8167 0.0015
1118tau-neutron mass ratio 1.891 11 0.000 17
1119tau-proton mass ratio 1.893 72 0.000 17
1120Thomson cross section 0.665 245 871 58 e-28 0.000 000 000 91 e-28 m^2
1121triton-electron mass ratio 5496.921 535 88 0.000 000 26
1122triton g factor 5.957 924 920 0.000 000 028
1123triton mag. mom. 1.504 609 503 e-26 0.000 000 012 e-26 J T^-1
1124triton mag. mom. to Bohr magneton ratio 1.622 393 6616 e-3 0.000 000 0076 e-3
1125triton mag. mom. to nuclear magneton ratio 2.978 962 460 0.000 000 014
1126triton mass 5.007 356 665 e-27 0.000 000 062 e-27 kg
1127triton mass energy equivalent 4.500 387 735 e-10 0.000 000 055 e-10 J
1128triton mass energy equivalent in MeV 2808.921 112 0.000 017 MeV
1129triton mass in u 3.015 500 716 32 0.000 000 000 11 u
1130triton molar mass 3.015 500 716 32 e-3 0.000 000 000 11 e-3 kg mol^-1
1131triton-proton mass ratio 2.993 717 033 48 0.000 000 000 22
1132unified atomic mass unit 1.660 539 040 e-27 0.000 000 020 e-27 kg
1133von Klitzing constant 25 812.807 4555 0.000 0059 ohm
1134weak mixing angle 0.2223 0.0021
1135Wien frequency displacement law constant 5.878 9238 e10 0.000 0034 e10 Hz K^-1
1136Wien wavelength displacement law constant 2.897 7729 e-3 0.000 0017 e-3 m K"""
1138txt2018 = """\
1139alpha particle-electron mass ratio 7294.299 541 42 0.000 000 24
1140alpha particle mass 6.644 657 3357 e-27 0.000 000 0020 e-27 kg
1141alpha particle mass energy equivalent 5.971 920 1914 e-10 0.000 000 0018 e-10 J
1142alpha particle mass energy equivalent in MeV 3727.379 4066 0.000 0011 MeV
1143alpha particle mass in u 4.001 506 179 127 0.000 000 000 063 u
1144alpha particle molar mass 4.001 506 1777 e-3 0.000 000 0012 e-3 kg mol^-1
1145alpha particle-proton mass ratio 3.972 599 690 09 0.000 000 000 22
1146alpha particle relative atomic mass 4.001 506 179 127 0.000 000 000 063
1147Angstrom star 1.000 014 95 e-10 0.000 000 90 e-10 m
1148atomic mass constant 1.660 539 066 60 e-27 0.000 000 000 50 e-27 kg
1149atomic mass constant energy equivalent 1.492 418 085 60 e-10 0.000 000 000 45 e-10 J
1150atomic mass constant energy equivalent in MeV 931.494 102 42 0.000 000 28 MeV
1151atomic mass unit-electron volt relationship 9.314 941 0242 e8 0.000 000 0028 e8 eV
1152atomic mass unit-hartree relationship 3.423 177 6874 e7 0.000 000 0010 e7 E_h
1153atomic mass unit-hertz relationship 2.252 342 718 71 e23 0.000 000 000 68 e23 Hz
1154atomic mass unit-inverse meter relationship 7.513 006 6104 e14 0.000 000 0023 e14 m^-1
1155atomic mass unit-joule relationship 1.492 418 085 60 e-10 0.000 000 000 45 e-10 J
1156atomic mass unit-kelvin relationship 1.080 954 019 16 e13 0.000 000 000 33 e13 K
1157atomic mass unit-kilogram relationship 1.660 539 066 60 e-27 0.000 000 000 50 e-27 kg
1158atomic unit of 1st hyperpolarizability 3.206 361 3061 e-53 0.000 000 0015 e-53 C^3 m^3 J^-2
1159atomic unit of 2nd hyperpolarizability 6.235 379 9905 e-65 0.000 000 0038 e-65 C^4 m^4 J^-3
1160atomic unit of action 1.054 571 817... e-34 (exact) J s
1161atomic unit of charge 1.602 176 634 e-19 (exact) C
1162atomic unit of charge density 1.081 202 384 57 e12 0.000 000 000 49 e12 C m^-3
1163atomic unit of current 6.623 618 237 510 e-3 0.000 000 000 013 e-3 A
1164atomic unit of electric dipole mom. 8.478 353 6255 e-30 0.000 000 0013 e-30 C m
1165atomic unit of electric field 5.142 206 747 63 e11 0.000 000 000 78 e11 V m^-1
1166atomic unit of electric field gradient 9.717 362 4292 e21 0.000 000 0029 e21 V m^-2
1167atomic unit of electric polarizability 1.648 777 274 36 e-41 0.000 000 000 50 e-41 C^2 m^2 J^-1
1168atomic unit of electric potential 27.211 386 245 988 0.000 000 000 053 V
1169atomic unit of electric quadrupole mom. 4.486 551 5246 e-40 0.000 000 0014 e-40 C m^2
1170atomic unit of energy 4.359 744 722 2071 e-18 0.000 000 000 0085 e-18 J
1171atomic unit of force 8.238 723 4983 e-8 0.000 000 0012 e-8 N
1172atomic unit of length 5.291 772 109 03 e-11 0.000 000 000 80 e-11 m
1173atomic unit of mag. dipole mom. 1.854 802 015 66 e-23 0.000 000 000 56 e-23 J T^-1
1174atomic unit of mag. flux density 2.350 517 567 58 e5 0.000 000 000 71 e5 T
1175atomic unit of magnetizability 7.891 036 6008 e-29 0.000 000 0048 e-29 J T^-2
1176atomic unit of mass 9.109 383 7015 e-31 0.000 000 0028 e-31 kg
1177atomic unit of momentum 1.992 851 914 10 e-24 0.000 000 000 30 e-24 kg m s^-1
1178atomic unit of permittivity 1.112 650 055 45 e-10 0.000 000 000 17 e-10 F m^-1
1179atomic unit of time 2.418 884 326 5857 e-17 0.000 000 000 0047 e-17 s
1180atomic unit of velocity 2.187 691 263 64 e6 0.000 000 000 33 e6 m s^-1
1181Avogadro constant 6.022 140 76 e23 (exact) mol^-1
1182Bohr magneton 9.274 010 0783 e-24 0.000 000 0028 e-24 J T^-1
1183Bohr magneton in eV/T 5.788 381 8060 e-5 0.000 000 0017 e-5 eV T^-1
1184Bohr magneton in Hz/T 1.399 624 493 61 e10 0.000 000 000 42 e10 Hz T^-1
1185Bohr magneton in inverse meter per tesla 46.686 447 783 0.000 000 014 m^-1 T^-1
1186Bohr magneton in K/T 0.671 713 815 63 0.000 000 000 20 K T^-1
1187Bohr radius 5.291 772 109 03 e-11 0.000 000 000 80 e-11 m
1188Boltzmann constant 1.380 649 e-23 (exact) J K^-1
1189Boltzmann constant in eV/K 8.617 333 262... e-5 (exact) eV K^-1
1190Boltzmann constant in Hz/K 2.083 661 912... e10 (exact) Hz K^-1
1191Boltzmann constant in inverse meter per kelvin 69.503 480 04... (exact) m^-1 K^-1
1192classical electron radius 2.817 940 3262 e-15 0.000 000 0013 e-15 m
1193Compton wavelength 2.426 310 238 67 e-12 0.000 000 000 73 e-12 m
1194conductance quantum 7.748 091 729... e-5 (exact) S
1195conventional value of ampere-90 1.000 000 088 87... (exact) A
1196conventional value of coulomb-90 1.000 000 088 87... (exact) C
1197conventional value of farad-90 0.999 999 982 20... (exact) F
1198conventional value of henry-90 1.000 000 017 79... (exact) H
1199conventional value of Josephson constant 483 597.9 e9 (exact) Hz V^-1
1200conventional value of ohm-90 1.000 000 017 79... (exact) ohm
1201conventional value of volt-90 1.000 000 106 66... (exact) V
1202conventional value of von Klitzing constant 25 812.807 (exact) ohm
1203conventional value of watt-90 1.000 000 195 53... (exact) W
1204Cu x unit 1.002 076 97 e-13 0.000 000 28 e-13 m
1205deuteron-electron mag. mom. ratio -4.664 345 551 e-4 0.000 000 012 e-4
1206deuteron-electron mass ratio 3670.482 967 88 0.000 000 13
1207deuteron g factor 0.857 438 2338 0.000 000 0022
1208deuteron mag. mom. 4.330 735 094 e-27 0.000 000 011 e-27 J T^-1
1209deuteron mag. mom. to Bohr magneton ratio 4.669 754 570 e-4 0.000 000 012 e-4
1210deuteron mag. mom. to nuclear magneton ratio 0.857 438 2338 0.000 000 0022
1211deuteron mass 3.343 583 7724 e-27 0.000 000 0010 e-27 kg
1212deuteron mass energy equivalent 3.005 063 231 02 e-10 0.000 000 000 91 e-10 J
1213deuteron mass energy equivalent in MeV 1875.612 942 57 0.000 000 57 MeV
1214deuteron mass in u 2.013 553 212 745 0.000 000 000 040 u
1215deuteron molar mass 2.013 553 212 05 e-3 0.000 000 000 61 e-3 kg mol^-1
1216deuteron-neutron mag. mom. ratio -0.448 206 53 0.000 000 11
1217deuteron-proton mag. mom. ratio 0.307 012 209 39 0.000 000 000 79
1218deuteron-proton mass ratio 1.999 007 501 39 0.000 000 000 11
1219deuteron relative atomic mass 2.013 553 212 745 0.000 000 000 040
1220deuteron rms charge radius 2.127 99 e-15 0.000 74 e-15 m
1221electron charge to mass quotient -1.758 820 010 76 e11 0.000 000 000 53 e11 C kg^-1
1222electron-deuteron mag. mom. ratio -2143.923 4915 0.000 0056
1223electron-deuteron mass ratio 2.724 437 107 462 e-4 0.000 000 000 096 e-4
1224electron g factor -2.002 319 304 362 56 0.000 000 000 000 35
1225electron gyromag. ratio 1.760 859 630 23 e11 0.000 000 000 53 e11 s^-1 T^-1
1226electron gyromag. ratio in MHz/T 28 024.951 4242 0.000 0085 MHz T^-1
1227electron-helion mass ratio 1.819 543 074 573 e-4 0.000 000 000 079 e-4
1228electron mag. mom. -9.284 764 7043 e-24 0.000 000 0028 e-24 J T^-1
1229electron mag. mom. anomaly 1.159 652 181 28 e-3 0.000 000 000 18 e-3
1230electron mag. mom. to Bohr magneton ratio -1.001 159 652 181 28 0.000 000 000 000 18
1231electron mag. mom. to nuclear magneton ratio -1838.281 971 88 0.000 000 11
1232electron mass 9.109 383 7015 e-31 0.000 000 0028 e-31 kg
1233electron mass energy equivalent 8.187 105 7769 e-14 0.000 000 0025 e-14 J
1234electron mass energy equivalent in MeV 0.510 998 950 00 0.000 000 000 15 MeV
1235electron mass in u 5.485 799 090 65 e-4 0.000 000 000 16 e-4 u
1236electron molar mass 5.485 799 0888 e-7 0.000 000 0017 e-7 kg mol^-1
1237electron-muon mag. mom. ratio 206.766 9883 0.000 0046
1238electron-muon mass ratio 4.836 331 69 e-3 0.000 000 11 e-3
1239electron-neutron mag. mom. ratio 960.920 50 0.000 23
1240electron-neutron mass ratio 5.438 673 4424 e-4 0.000 000 0026 e-4
1241electron-proton mag. mom. ratio -658.210 687 89 0.000 000 20
1242electron-proton mass ratio 5.446 170 214 87 e-4 0.000 000 000 33 e-4
1243electron relative atomic mass 5.485 799 090 65 e-4 0.000 000 000 16 e-4
1244electron-tau mass ratio 2.875 85 e-4 0.000 19 e-4
1245electron to alpha particle mass ratio 1.370 933 554 787 e-4 0.000 000 000 045 e-4
1246electron to shielded helion mag. mom. ratio 864.058 257 0.000 010
1247electron to shielded proton mag. mom. ratio -658.227 5971 0.000 0072
1248electron-triton mass ratio 1.819 200 062 251 e-4 0.000 000 000 090 e-4
1249electron volt 1.602 176 634 e-19 (exact) J
1250electron volt-atomic mass unit relationship 1.073 544 102 33 e-9 0.000 000 000 32 e-9 u
1251electron volt-hartree relationship 3.674 932 217 5655 e-2 0.000 000 000 0071 e-2 E_h
1252electron volt-hertz relationship 2.417 989 242... e14 (exact) Hz
1253electron volt-inverse meter relationship 8.065 543 937... e5 (exact) m^-1
1254electron volt-joule relationship 1.602 176 634 e-19 (exact) J
1255electron volt-kelvin relationship 1.160 451 812... e4 (exact) K
1256electron volt-kilogram relationship 1.782 661 921... e-36 (exact) kg
1257elementary charge 1.602 176 634 e-19 (exact) C
1258elementary charge over h-bar 1.519 267 447... e15 (exact) A J^-1
1259Faraday constant 96 485.332 12... (exact) C mol^-1
1260Fermi coupling constant 1.166 3787 e-5 0.000 0006 e-5 GeV^-2
1261fine-structure constant 7.297 352 5693 e-3 0.000 000 0011 e-3
1262first radiation constant 3.741 771 852... e-16 (exact) W m^2
1263first radiation constant for spectral radiance 1.191 042 972... e-16 (exact) W m^2 sr^-1
1264hartree-atomic mass unit relationship 2.921 262 322 05 e-8 0.000 000 000 88 e-8 u
1265hartree-electron volt relationship 27.211 386 245 988 0.000 000 000 053 eV
1266Hartree energy 4.359 744 722 2071 e-18 0.000 000 000 0085 e-18 J
1267Hartree energy in eV 27.211 386 245 988 0.000 000 000 053 eV
1268hartree-hertz relationship 6.579 683 920 502 e15 0.000 000 000 013 e15 Hz
1269hartree-inverse meter relationship 2.194 746 313 6320 e7 0.000 000 000 0043 e7 m^-1
1270hartree-joule relationship 4.359 744 722 2071 e-18 0.000 000 000 0085 e-18 J
1271hartree-kelvin relationship 3.157 750 248 0407 e5 0.000 000 000 0061 e5 K
1272hartree-kilogram relationship 4.850 870 209 5432 e-35 0.000 000 000 0094 e-35 kg
1273helion-electron mass ratio 5495.885 280 07 0.000 000 24
1274helion g factor -4.255 250 615 0.000 000 050
1275helion mag. mom. -1.074 617 532 e-26 0.000 000 013 e-26 J T^-1
1276helion mag. mom. to Bohr magneton ratio -1.158 740 958 e-3 0.000 000 014 e-3
1277helion mag. mom. to nuclear magneton ratio -2.127 625 307 0.000 000 025
1278helion mass 5.006 412 7796 e-27 0.000 000 0015 e-27 kg
1279helion mass energy equivalent 4.499 539 4125 e-10 0.000 000 0014 e-10 J
1280helion mass energy equivalent in MeV 2808.391 607 43 0.000 000 85 MeV
1281helion mass in u 3.014 932 247 175 0.000 000 000 097 u
1282helion molar mass 3.014 932 246 13 e-3 0.000 000 000 91 e-3 kg mol^-1
1283helion-proton mass ratio 2.993 152 671 67 0.000 000 000 13
1284helion relative atomic mass 3.014 932 247 175 0.000 000 000 097
1285helion shielding shift 5.996 743 e-5 0.000 010 e-5
1286hertz-atomic mass unit relationship 4.439 821 6652 e-24 0.000 000 0013 e-24 u
1287hertz-electron volt relationship 4.135 667 696... e-15 (exact) eV
1288hertz-hartree relationship 1.519 829 846 0570 e-16 0.000 000 000 0029 e-16 E_h
1289hertz-inverse meter relationship 3.335 640 951... e-9 (exact) m^-1
1290hertz-joule relationship 6.626 070 15 e-34 (exact) J
1291hertz-kelvin relationship 4.799 243 073... e-11 (exact) K
1292hertz-kilogram relationship 7.372 497 323... e-51 (exact) kg
1293hyperfine transition frequency of Cs-133 9 192 631 770 (exact) Hz
1294inverse fine-structure constant 137.035 999 084 0.000 000 021
1295inverse meter-atomic mass unit relationship 1.331 025 050 10 e-15 0.000 000 000 40 e-15 u
1296inverse meter-electron volt relationship 1.239 841 984... e-6 (exact) eV
1297inverse meter-hartree relationship 4.556 335 252 9120 e-8 0.000 000 000 0088 e-8 E_h
1298inverse meter-hertz relationship 299 792 458 (exact) Hz
1299inverse meter-joule relationship 1.986 445 857... e-25 (exact) J
1300inverse meter-kelvin relationship 1.438 776 877... e-2 (exact) K
1301inverse meter-kilogram relationship 2.210 219 094... e-42 (exact) kg
1302inverse of conductance quantum 12 906.403 72... (exact) ohm
1303Josephson constant 483 597.848 4... e9 (exact) Hz V^-1
1304joule-atomic mass unit relationship 6.700 535 2565 e9 0.000 000 0020 e9 u
1305joule-electron volt relationship 6.241 509 074... e18 (exact) eV
1306joule-hartree relationship 2.293 712 278 3963 e17 0.000 000 000 0045 e17 E_h
1307joule-hertz relationship 1.509 190 179... e33 (exact) Hz
1308joule-inverse meter relationship 5.034 116 567... e24 (exact) m^-1
1309joule-kelvin relationship 7.242 970 516... e22 (exact) K
1310joule-kilogram relationship 1.112 650 056... e-17 (exact) kg
1311kelvin-atomic mass unit relationship 9.251 087 3014 e-14 0.000 000 0028 e-14 u
1312kelvin-electron volt relationship 8.617 333 262... e-5 (exact) eV
1313kelvin-hartree relationship 3.166 811 563 4556 e-6 0.000 000 000 0061 e-6 E_h
1314kelvin-hertz relationship 2.083 661 912... e10 (exact) Hz
1315kelvin-inverse meter relationship 69.503 480 04... (exact) m^-1
1316kelvin-joule relationship 1.380 649 e-23 (exact) J
1317kelvin-kilogram relationship 1.536 179 187... e-40 (exact) kg
1318kilogram-atomic mass unit relationship 6.022 140 7621 e26 0.000 000 0018 e26 u
1319kilogram-electron volt relationship 5.609 588 603... e35 (exact) eV
1320kilogram-hartree relationship 2.061 485 788 7409 e34 0.000 000 000 0040 e34 E_h
1321kilogram-hertz relationship 1.356 392 489... e50 (exact) Hz
1322kilogram-inverse meter relationship 4.524 438 335... e41 (exact) m^-1
1323kilogram-joule relationship 8.987 551 787... e16 (exact) J
1324kilogram-kelvin relationship 6.509 657 260... e39 (exact) K
1325lattice parameter of silicon 5.431 020 511 e-10 0.000 000 089 e-10 m
1326lattice spacing of ideal Si (220) 1.920 155 716 e-10 0.000 000 032 e-10 m
1327Loschmidt constant (273.15 K, 100 kPa) 2.651 645 804... e25 (exact) m^-3
1328Loschmidt constant (273.15 K, 101.325 kPa) 2.686 780 111... e25 (exact) m^-3
1329luminous efficacy 683 (exact) lm W^-1
1330mag. flux quantum 2.067 833 848... e-15 (exact) Wb
1331molar gas constant 8.314 462 618... (exact) J mol^-1 K^-1
1332molar mass constant 0.999 999 999 65 e-3 0.000 000 000 30 e-3 kg mol^-1
1333molar mass of carbon-12 11.999 999 9958 e-3 0.000 000 0036 e-3 kg mol^-1
1334molar Planck constant 3.990 312 712... e-10 (exact) J Hz^-1 mol^-1
1335molar volume of ideal gas (273.15 K, 100 kPa) 22.710 954 64... e-3 (exact) m^3 mol^-1
1336molar volume of ideal gas (273.15 K, 101.325 kPa) 22.413 969 54... e-3 (exact) m^3 mol^-1
1337molar volume of silicon 1.205 883 199 e-5 0.000 000 060 e-5 m^3 mol^-1
1338Mo x unit 1.002 099 52 e-13 0.000 000 53 e-13 m
1339muon Compton wavelength 1.173 444 110 e-14 0.000 000 026 e-14 m
1340muon-electron mass ratio 206.768 2830 0.000 0046
1341muon g factor -2.002 331 8418 0.000 000 0013
1342muon mag. mom. -4.490 448 30 e-26 0.000 000 10 e-26 J T^-1
1343muon mag. mom. anomaly 1.165 920 89 e-3 0.000 000 63 e-3
1344muon mag. mom. to Bohr magneton ratio -4.841 970 47 e-3 0.000 000 11 e-3
1345muon mag. mom. to nuclear magneton ratio -8.890 597 03 0.000 000 20
1346muon mass 1.883 531 627 e-28 0.000 000 042 e-28 kg
1347muon mass energy equivalent 1.692 833 804 e-11 0.000 000 038 e-11 J
1348muon mass energy equivalent in MeV 105.658 3755 0.000 0023 MeV
1349muon mass in u 0.113 428 9259 0.000 000 0025 u
1350muon molar mass 1.134 289 259 e-4 0.000 000 025 e-4 kg mol^-1
1351muon-neutron mass ratio 0.112 454 5170 0.000 000 0025
1352muon-proton mag. mom. ratio -3.183 345 142 0.000 000 071
1353muon-proton mass ratio 0.112 609 5264 0.000 000 0025
1354muon-tau mass ratio 5.946 35 e-2 0.000 40 e-2
1355natural unit of action 1.054 571 817... e-34 (exact) J s
1356natural unit of action in eV s 6.582 119 569... e-16 (exact) eV s
1357natural unit of energy 8.187 105 7769 e-14 0.000 000 0025 e-14 J
1358natural unit of energy in MeV 0.510 998 950 00 0.000 000 000 15 MeV
1359natural unit of length 3.861 592 6796 e-13 0.000 000 0012 e-13 m
1360natural unit of mass 9.109 383 7015 e-31 0.000 000 0028 e-31 kg
1361natural unit of momentum 2.730 924 530 75 e-22 0.000 000 000 82 e-22 kg m s^-1
1362natural unit of momentum in MeV/c 0.510 998 950 00 0.000 000 000 15 MeV/c
1363natural unit of time 1.288 088 668 19 e-21 0.000 000 000 39 e-21 s
1364natural unit of velocity 299 792 458 (exact) m s^-1
1365neutron Compton wavelength 1.319 590 905 81 e-15 0.000 000 000 75 e-15 m
1366neutron-electron mag. mom. ratio 1.040 668 82 e-3 0.000 000 25 e-3
1367neutron-electron mass ratio 1838.683 661 73 0.000 000 89
1368neutron g factor -3.826 085 45 0.000 000 90
1369neutron gyromag. ratio 1.832 471 71 e8 0.000 000 43 e8 s^-1 T^-1
1370neutron gyromag. ratio in MHz/T 29.164 6931 0.000 0069 MHz T^-1
1371neutron mag. mom. -9.662 3651 e-27 0.000 0023 e-27 J T^-1
1372neutron mag. mom. to Bohr magneton ratio -1.041 875 63 e-3 0.000 000 25 e-3
1373neutron mag. mom. to nuclear magneton ratio -1.913 042 73 0.000 000 45
1374neutron mass 1.674 927 498 04 e-27 0.000 000 000 95 e-27 kg
1375neutron mass energy equivalent 1.505 349 762 87 e-10 0.000 000 000 86 e-10 J
1376neutron mass energy equivalent in MeV 939.565 420 52 0.000 000 54 MeV
1377neutron mass in u 1.008 664 915 95 0.000 000 000 49 u
1378neutron molar mass 1.008 664 915 60 e-3 0.000 000 000 57 e-3 kg mol^-1
1379neutron-muon mass ratio 8.892 484 06 0.000 000 20
1380neutron-proton mag. mom. ratio -0.684 979 34 0.000 000 16
1381neutron-proton mass difference 2.305 574 35 e-30 0.000 000 82 e-30 kg
1382neutron-proton mass difference energy equivalent 2.072 146 89 e-13 0.000 000 74 e-13 J
1383neutron-proton mass difference energy equivalent in MeV 1.293 332 36 0.000 000 46 MeV
1384neutron-proton mass difference in u 1.388 449 33 e-3 0.000 000 49 e-3 u
1385neutron-proton mass ratio 1.001 378 419 31 0.000 000 000 49
1386neutron relative atomic mass 1.008 664 915 95 0.000 000 000 49
1387neutron-tau mass ratio 0.528 779 0.000 036
1388neutron to shielded proton mag. mom. ratio -0.684 996 94 0.000 000 16
1389Newtonian constant of gravitation 6.674 30 e-11 0.000 15 e-11 m^3 kg^-1 s^-2
1390Newtonian constant of gravitation over h-bar c 6.708 83 e-39 0.000 15 e-39 (GeV/c^2)^-2
1391nuclear magneton 5.050 783 7461 e-27 0.000 000 0015 e-27 J T^-1
1392nuclear magneton in eV/T 3.152 451 258 44 e-8 0.000 000 000 96 e-8 eV T^-1
1393nuclear magneton in inverse meter per tesla 2.542 623 413 53 e-2 0.000 000 000 78 e-2 m^-1 T^-1
1394nuclear magneton in K/T 3.658 267 7756 e-4 0.000 000 0011 e-4 K T^-1
1395nuclear magneton in MHz/T 7.622 593 2291 0.000 000 0023 MHz T^-1
1396Planck constant 6.626 070 15 e-34 (exact) J Hz^-1
1397Planck constant in eV/Hz 4.135 667 696... e-15 (exact) eV Hz^-1
1398Planck length 1.616 255 e-35 0.000 018 e-35 m
1399Planck mass 2.176 434 e-8 0.000 024 e-8 kg
1400Planck mass energy equivalent in GeV 1.220 890 e19 0.000 014 e19 GeV
1401Planck temperature 1.416 784 e32 0.000 016 e32 K
1402Planck time 5.391 247 e-44 0.000 060 e-44 s
1403proton charge to mass quotient 9.578 833 1560 e7 0.000 000 0029 e7 C kg^-1
1404proton Compton wavelength 1.321 409 855 39 e-15 0.000 000 000 40 e-15 m
1405proton-electron mass ratio 1836.152 673 43 0.000 000 11
1406proton g factor 5.585 694 6893 0.000 000 0016
1407proton gyromag. ratio 2.675 221 8744 e8 0.000 000 0011 e8 s^-1 T^-1
1408proton gyromag. ratio in MHz/T 42.577 478 518 0.000 000 018 MHz T^-1
1409proton mag. mom. 1.410 606 797 36 e-26 0.000 000 000 60 e-26 J T^-1
1410proton mag. mom. to Bohr magneton ratio 1.521 032 202 30 e-3 0.000 000 000 46 e-3
1411proton mag. mom. to nuclear magneton ratio 2.792 847 344 63 0.000 000 000 82
1412proton mag. shielding correction 2.5689 e-5 0.0011 e-5
1413proton mass 1.672 621 923 69 e-27 0.000 000 000 51 e-27 kg
1414proton mass energy equivalent 1.503 277 615 98 e-10 0.000 000 000 46 e-10 J
1415proton mass energy equivalent in MeV 938.272 088 16 0.000 000 29 MeV
1416proton mass in u 1.007 276 466 621 0.000 000 000 053 u
1417proton molar mass 1.007 276 466 27 e-3 0.000 000 000 31 e-3 kg mol^-1
1418proton-muon mass ratio 8.880 243 37 0.000 000 20
1419proton-neutron mag. mom. ratio -1.459 898 05 0.000 000 34
1420proton-neutron mass ratio 0.998 623 478 12 0.000 000 000 49
1421proton relative atomic mass 1.007 276 466 621 0.000 000 000 053
1422proton rms charge radius 8.414 e-16 0.019 e-16 m
1423proton-tau mass ratio 0.528 051 0.000 036
1424quantum of circulation 3.636 947 5516 e-4 0.000 000 0011 e-4 m^2 s^-1
1425quantum of circulation times 2 7.273 895 1032 e-4 0.000 000 0022 e-4 m^2 s^-1
1426reduced Compton wavelength 3.861 592 6796 e-13 0.000 000 0012 e-13 m
1427reduced muon Compton wavelength 1.867 594 306 e-15 0.000 000 042 e-15 m
1428reduced neutron Compton wavelength 2.100 194 1552 e-16 0.000 000 0012 e-16 m
1429reduced Planck constant 1.054 571 817... e-34 (exact) J s
1430reduced Planck constant in eV s 6.582 119 569... e-16 (exact) eV s
1431reduced Planck constant times c in MeV fm 197.326 980 4... (exact) MeV fm
1432reduced proton Compton wavelength 2.103 089 103 36 e-16 0.000 000 000 64 e-16 m
1433reduced tau Compton wavelength 1.110 538 e-16 0.000 075 e-16 m
1434Rydberg constant 10 973 731.568 160 0.000 021 m^-1
1435Rydberg constant times c in Hz 3.289 841 960 2508 e15 0.000 000 000 0064 e15 Hz
1436Rydberg constant times hc in eV 13.605 693 122 994 0.000 000 000 026 eV
1437Rydberg constant times hc in J 2.179 872 361 1035 e-18 0.000 000 000 0042 e-18 J
1438Sackur-Tetrode constant (1 K, 100 kPa) -1.151 707 537 06 0.000 000 000 45
1439Sackur-Tetrode constant (1 K, 101.325 kPa) -1.164 870 523 58 0.000 000 000 45
1440second radiation constant 1.438 776 877... e-2 (exact) m K
1441shielded helion gyromag. ratio 2.037 894 569 e8 0.000 000 024 e8 s^-1 T^-1
1442shielded helion gyromag. ratio in MHz/T 32.434 099 42 0.000 000 38 MHz T^-1
1443shielded helion mag. mom. -1.074 553 090 e-26 0.000 000 013 e-26 J T^-1
1444shielded helion mag. mom. to Bohr magneton ratio -1.158 671 471 e-3 0.000 000 014 e-3
1445shielded helion mag. mom. to nuclear magneton ratio -2.127 497 719 0.000 000 025
1446shielded helion to proton mag. mom. ratio -0.761 766 5618 0.000 000 0089
1447shielded helion to shielded proton mag. mom. ratio -0.761 786 1313 0.000 000 0033
1448shielded proton gyromag. ratio 2.675 153 151 e8 0.000 000 029 e8 s^-1 T^-1
1449shielded proton gyromag. ratio in MHz/T 42.576 384 74 0.000 000 46 MHz T^-1
1450shielded proton mag. mom. 1.410 570 560 e-26 0.000 000 015 e-26 J T^-1
1451shielded proton mag. mom. to Bohr magneton ratio 1.520 993 128 e-3 0.000 000 017 e-3
1452shielded proton mag. mom. to nuclear magneton ratio 2.792 775 599 0.000 000 030
1453shielding difference of d and p in HD 2.0200 e-8 0.0020 e-8
1454shielding difference of t and p in HT 2.4140 e-8 0.0020 e-8
1455speed of light in vacuum 299 792 458 (exact) m s^-1
1456standard acceleration of gravity 9.806 65 (exact) m s^-2
1457standard atmosphere 101 325 (exact) Pa
1458standard-state pressure 100 000 (exact) Pa
1459Stefan-Boltzmann constant 5.670 374 419... e-8 (exact) W m^-2 K^-4
1460tau Compton wavelength 6.977 71 e-16 0.000 47 e-16 m
1461tau-electron mass ratio 3477.23 0.23
1462tau energy equivalent 1776.86 0.12 MeV
1463tau mass 3.167 54 e-27 0.000 21 e-27 kg
1464tau mass energy equivalent 2.846 84 e-10 0.000 19 e-10 J
1465tau mass in u 1.907 54 0.000 13 u
1466tau molar mass 1.907 54 e-3 0.000 13 e-3 kg mol^-1
1467tau-muon mass ratio 16.8170 0.0011
1468tau-neutron mass ratio 1.891 15 0.000 13
1469tau-proton mass ratio 1.893 76 0.000 13
1470Thomson cross section 6.652 458 7321 e-29 0.000 000 0060 e-29 m^2
1471triton-electron mass ratio 5496.921 535 73 0.000 000 27
1472triton g factor 5.957 924 931 0.000 000 012
1473triton mag. mom. 1.504 609 5202 e-26 0.000 000 0030 e-26 J T^-1
1474triton mag. mom. to Bohr magneton ratio 1.622 393 6651 e-3 0.000 000 0032 e-3
1475triton mag. mom. to nuclear magneton ratio 2.978 962 4656 0.000 000 0059
1476triton mass 5.007 356 7446 e-27 0.000 000 0015 e-27 kg
1477triton mass energy equivalent 4.500 387 8060 e-10 0.000 000 0014 e-10 J
1478triton mass energy equivalent in MeV 2808.921 132 98 0.000 000 85 MeV
1479triton mass in u 3.015 500 716 21 0.000 000 000 12 u
1480triton molar mass 3.015 500 715 17 e-3 0.000 000 000 92 e-3 kg mol^-1
1481triton-proton mass ratio 2.993 717 034 14 0.000 000 000 15
1482triton relative atomic mass 3.015 500 716 21 0.000 000 000 12
1483triton to proton mag. mom. ratio 1.066 639 9191 0.000 000 0021
1484unified atomic mass unit 1.660 539 066 60 e-27 0.000 000 000 50 e-27 kg
1485vacuum electric permittivity 8.854 187 8128 e-12 0.000 000 0013 e-12 F m^-1
1486vacuum mag. permeability 1.256 637 062 12 e-6 0.000 000 000 19 e-6 N A^-2
1487von Klitzing constant 25 812.807 45... (exact) ohm
1488weak mixing angle 0.222 90 0.000 30
1489Wien frequency displacement law constant 5.878 925 757... e10 (exact) Hz K^-1
1490Wien wavelength displacement law constant 2.897 771 955... e-3 (exact) m K
1491W to Z mass ratio 0.881 53 0.000 17 """
1493# -----------------------------------------------------------------------------
1495physical_constants = {}
1498def parse_constants_2002to2014(d):
1499 constants = {}
1500 for line in d.split('\n'):
1501 name = line[:55].rstrip()
1502 val = line[55:77].replace(' ', '').replace('...', '')
1503 val = float(val)
1504 uncert = line[77:99].replace(' ', '').replace('(exact)', '0')
1505 uncert = float(uncert)
1506 units = line[99:].rstrip()
1507 constants[name] = (val, units, uncert)
1508 return constants
1510def parse_constants_2018toXXXX(d):
1511 constants = {}
1512 for line in d.split('\n'):
1513 name = line[:60].rstrip()
1514 val = line[60:85].replace(' ', '').replace('...', '')
1515 val = float(val)
1516 uncert = line[85:110].replace(' ', '').replace('(exact)', '0')
1517 uncert = float(uncert)
1518 units = line[110:].rstrip()
1519 constants[name] = (val, units, uncert)
1520 return constants
1523_physical_constants_2002 = parse_constants_2002to2014(txt2002)
1524_physical_constants_2006 = parse_constants_2002to2014(txt2006)
1525_physical_constants_2010 = parse_constants_2002to2014(txt2010)
1526_physical_constants_2014 = parse_constants_2002to2014(txt2014)
1527_physical_constants_2018 = parse_constants_2018toXXXX(txt2018)
1530physical_constants.update(_physical_constants_2002)
1531physical_constants.update(_physical_constants_2006)
1532physical_constants.update(_physical_constants_2010)
1533physical_constants.update(_physical_constants_2014)
1534physical_constants.update(_physical_constants_2018)
1535_current_constants = _physical_constants_2018
1536_current_codata = "CODATA 2018"
1538# check obsolete values
1539_obsolete_constants = {}
1540for k in physical_constants:
1541 if k not in _current_constants:
1542 _obsolete_constants[k] = True
1544# generate some additional aliases
1545_aliases = {}
1546for k in _physical_constants_2002:
1547 if 'magn.' in k:
1548 _aliases[k] = k.replace('magn.', 'mag.')
1549for k in _physical_constants_2006:
1550 if 'momentum' in k:
1551 _aliases[k] = k.replace('momentum', 'mom.um')
1552for k in _physical_constants_2018:
1553 if 'momentum' in k:
1554 _aliases[k] = k.replace('momentum', 'mom.um')
1556# CODATA 2018: renamed and no longer exact; use as aliases
1557_aliases['mag. constant'] = 'vacuum mag. permeability'
1558_aliases['electric constant'] = 'vacuum electric permittivity'
1561class ConstantWarning(DeprecationWarning):
1562 """Accessing a constant no longer in current CODATA data set"""
1563 pass
1566def _check_obsolete(key):
1567 if key in _obsolete_constants and key not in _aliases:
1568 warnings.warn("Constant '%s' is not in current %s data set" % (
1569 key, _current_codata), ConstantWarning)
1572def value(key):
1573 """
1574 Value in physical_constants indexed by key
1576 Parameters
1577 ----------
1578 key : Python string or unicode
1579 Key in dictionary `physical_constants`
1581 Returns
1582 -------
1583 value : float
1584 Value in `physical_constants` corresponding to `key`
1586 Examples
1587 --------
1588 >>> from scipy import constants
1589 >>> constants.value(u'elementary charge')
1590 1.602176634e-19
1592 """
1593 _check_obsolete(key)
1594 return physical_constants[key][0]
1597def unit(key):
1598 """
1599 Unit in physical_constants indexed by key
1601 Parameters
1602 ----------
1603 key : Python string or unicode
1604 Key in dictionary `physical_constants`
1606 Returns
1607 -------
1608 unit : Python string
1609 Unit in `physical_constants` corresponding to `key`
1611 Examples
1612 --------
1613 >>> from scipy import constants
1614 >>> constants.unit(u'proton mass')
1615 'kg'
1617 """
1618 _check_obsolete(key)
1619 return physical_constants[key][1]
1622def precision(key):
1623 """
1624 Relative precision in physical_constants indexed by key
1626 Parameters
1627 ----------
1628 key : Python string or unicode
1629 Key in dictionary `physical_constants`
1631 Returns
1632 -------
1633 prec : float
1634 Relative precision in `physical_constants` corresponding to `key`
1636 Examples
1637 --------
1638 >>> from scipy import constants
1639 >>> constants.precision(u'proton mass')
1640 5.1e-37
1642 """
1643 _check_obsolete(key)
1644 return physical_constants[key][2] / physical_constants[key][0]
1647def find(sub=None, disp=False):
1648 """
1649 Return list of physical_constant keys containing a given string.
1651 Parameters
1652 ----------
1653 sub : str, unicode
1654 Sub-string to search keys for. By default, return all keys.
1655 disp : bool
1656 If True, print the keys that are found and return None.
1657 Otherwise, return the list of keys without printing anything.
1659 Returns
1660 -------
1661 keys : list or None
1662 If `disp` is False, the list of keys is returned.
1663 Otherwise, None is returned.
1665 Examples
1666 --------
1667 >>> from scipy.constants import find, physical_constants
1669 Which keys in the ``physical_constants`` dictionary contain 'boltzmann'?
1671 >>> find('boltzmann')
1672 ['Boltzmann constant',
1673 'Boltzmann constant in Hz/K',
1674 'Boltzmann constant in eV/K',
1675 'Boltzmann constant in inverse meter per kelvin',
1676 'Stefan-Boltzmann constant']
1678 Get the constant called 'Boltzmann constant in Hz/K':
1680 >>> physical_constants['Boltzmann constant in Hz/K']
1681 (20836619120.0, 'Hz K^-1', 0.0)
1683 Find constants with 'radius' in the key:
1685 >>> find('radius')
1686 ['Bohr radius',
1687 'classical electron radius',
1688 'deuteron rms charge radius',
1689 'proton rms charge radius']
1690 >>> physical_constants['classical electron radius']
1691 (2.8179403262e-15, 'm', 1.3e-24)
1693 """
1694 if sub is None:
1695 result = list(_current_constants.keys())
1696 else:
1697 result = [key for key in _current_constants
1698 if sub.lower() in key.lower()]
1700 result.sort()
1701 if disp:
1702 for key in result:
1703 print(key)
1704 return
1705 else:
1706 return result
1709c = value('speed of light in vacuum')
1710mu0 = value('vacuum mag. permeability')
1711epsilon0 = value('vacuum electric permittivity')
1713# Table is lacking some digits for exact values: calculate from definition
1714exact_values = {
1715 'joule-kilogram relationship': (1 / (c * c), 'kg', 0.0),
1716 'kilogram-joule relationship': (c * c, 'J', 0.0),
1717 'hertz-inverse meter relationship': (1 / c, 'm^-1', 0.0),
1719 # The following derived quantities are no longer exact (CODATA2018):
1720 # specify separately
1721 'characteristic impedance of vacuum': (
1722 sqrt(mu0 / epsilon0), 'ohm',
1723 sqrt(mu0 / epsilon0) * 0.5 * (
1724 physical_constants['vacuum mag. permeability'][2] / mu0
1725 + physical_constants['vacuum electric permittivity'][2] / epsilon0))
1726}
1728# sanity check
1729for key in exact_values:
1730 val = physical_constants[key][0]
1731 if abs(exact_values[key][0] - val) / val > 1e-9:
1732 raise ValueError("Constants.codata: exact values too far off.")
1733 if exact_values[key][2] == 0 and physical_constants[key][2] != 0:
1734 raise ValueError("Constants.codata: value not exact")
1736physical_constants.update(exact_values)
1738_tested_keys = ['natural unit of velocity',
1739 'natural unit of action',
1740 'natural unit of action in eV s',
1741 'natural unit of mass',
1742 'natural unit of energy',
1743 'natural unit of energy in MeV',
1744 'natural unit of mom.um',
1745 'natural unit of mom.um in MeV/c',
1746 'natural unit of length',
1747 'natural unit of time']
1749# finally, insert aliases for values
1750for k, v in list(_aliases.items()):
1751 if v in _current_constants or v in _tested_keys:
1752 physical_constants[k] = physical_constants[v]
1753 else:
1754 del _aliases[k]