matminer.descriptors package¶
Submodules¶
matminer.descriptors.add_descriptors module¶
matminer.descriptors.bandstructure_features module¶
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matminer.descriptors.bandstructure_features.
absolute_band_positions_bpe
(bs, target_gap=None, **kwargs)¶ Absolute VBM and CBM positions with respect to branch point energy
- Args:
- bs: Bandstructure object target_gap: if a better band gap is known, shift band positions by this gap **kwargs: arguments to feed into branch point energy code
- Returns:
- (vbm, cbm) - tuple of floats
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matminer.descriptors.bandstructure_features.
branch_point_energy
(bs, n_vb=1, n_cb=1)¶ Get the branch point energy as defined by: Schleife, Fuchs, Rodi, Furthmuller, Bechstedt, APL 94, 012104 (2009)
- Args:
- bs: (BandStructure) - uniform mesh bandstructure object n_vb: number of valence bands to include n_cb: number of conduction bands to include
Returns: (int) branch point energy on same energy scale as BS eigenvalues
matminer.descriptors.composition_features module¶
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matminer.descriptors.composition_features.
band_center
(comp)¶ Estimate absolution position of band center using geometric mean of electronegativity Ref: Butler, M. a. & Ginley, D. S. Prediction of Flatband Potentials at Semiconductor-Electrolyte Interfaces from Atomic Electronegativities. J. Electrochem. Soc. 125, 228 (1978).
- Args:
- comp: (Composition)
Returns: (float) band center
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matminer.descriptors.composition_features.
get_cohesive_energy
(comp)¶ Get cohesive energy of compound by subtracting elemental cohesive energies from the formation energy of the compund. Elemental cohesive energies are taken from http://www.knowledgedoor.com/2/elements_handbook/cohesive_energy.html. Most of them are taken from “Charles Kittel: Introduction to Solid State Physics, 8th edition. Hoboken, NJ: John Wiley & Sons, Inc, 2005, p. 50.”
- Args:
- comp: (str) compound composition, eg: “NaCl”
Returns: (float) cohesive energy of compound
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matminer.descriptors.composition_features.
get_holder_mean
(data_lst, power)¶ Get Holder mean
- Args:
- data_lst: (list/array) of values power: (int/float) non-zero real number
Returns: Holder mean
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matminer.descriptors.composition_features.
get_magpie_descriptor
(comp, descriptor_name)¶ Get descriptor data for elements in a compound from the Magpie data repository.
- Args:
comp: (str) compound composition, eg: “NaCl” descriptor_name: name of Magpie descriptor needed. Find the entire list at
Returns: (list) of descriptor values for each atom in the composition
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matminer.descriptors.composition_features.
get_pymatgen_descriptor
(comp, prop)¶ Get descriptor data for elements in a compound from pymatgen.
- Args:
comp: (str) compound composition, eg: “NaCl” prop: (str) pymatgen element attribute, as defined in the Element class at
Returns: (list) of values containing descriptor floats for each atom in the compound
matminer.descriptors.structure_features module¶
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matminer.descriptors.structure_features.
density
(s)¶
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matminer.descriptors.structure_features.
get_packing_fraction
(s)¶
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matminer.descriptors.structure_features.
get_rdf
(structure, cutoff=20.0, bin_size=0.1)¶ Calculate rdf fingerprint of a given structure
- Args:
- structure: pymatgen structure object cutoff: (int/float) distance to calculate rdf up to bin_size: (int/float) size of bin to obtain rdf for
Returns: (dict) rdf in dict format where keys indicate bin distance and values are calculated rdf for that bin.
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matminer.descriptors.structure_features.
get_rdf_peaks
(dist_rdf)¶ Get location of highest and second highest peaks in rdf of a structure.
- Args:
- dist_rdf: (dict) as output by the function “get_rdf”, keys correspond to distances and values correspond to rdf.
Returns: (tuple) of distances highest and second highest peaks.
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matminer.descriptors.structure_features.
get_redf
(struct, cutoff=None, dr=0.05)¶ This function permits the calculation of the crystal structure-inherent electronic radial distribution function (ReDF) according to Willighagen et al., Acta Cryst., 2005, B61, 29-36. The ReDF is a structure-integral RDF (i.e., summed over all sites) in which the positions of neighboring sites are weighted by electrostatic interactions inferred from atomic partial charges. Atomic charges are obtained from the ValenceIonicRadiusEvaluator class.
- Args:
struct (Structure): input Structure object. cutoff (float): distance up to which the ReDF is to be
calculated (default: longest diagaonal in primitive cell)dr (float): width of bins (“x”-axis) of ReDF (default: 0.05 A).
- Returns: (dict) a copy of the electronic radial distribution functions (ReDF) as a dictionary. The distance list
- (“x”-axis values of ReDF) can be accessed via key ‘distances’; the ReDF itself via key ‘redf’.
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matminer.descriptors.structure_features.
get_vol_per_site
(s)¶