Descriptors

pyscal can calculate the following descriptors:

Isolating local environment: fixed cutoff, adaptive cutoff, SANN, and Voronoi.	Method	Example
Steinhardt bond-orientational parameters: \(q_l\) and averaged \(\bar{q}_l\) for structure identification.	Method	Example
Wigner \(W_l\) parameters: third-order rotational invariants that distinguish cubic structures.	Method	Example
Minkowski structure metrics: Voronoi-area-weighted, parameter-free \(q_l\).	Method	Example
Solid identification and clustering: distinguish solid atoms in a liquid; cluster atoms by any property.	Method	Example
Disorder parameters: identify disordered regions in crystalline materials.	Method	Example
Angular and \(\chi\) parameters: quantify bond angles, useful for tetrahedral and other crystal environments.	Method	Example
Ackland-Jones classification: fcc / bcc / hcp / icosahedral labels from angular histograms.	Method	Example
Coordination measures: coordination number, effective and generalized coordination.	Method	Example
Angular and bond length distributions: ADF and BLDF as local fingerprints.	Method	Example
Voronoi tessellation: structural vector and Voronoi volume.	Method	Example
Centrosymmetry parameter: find breaks in the ordered crystal.	Method	Example
Common neighbor analysis: CNA and adaptive CNA for bcc, fcc, hcp; diamond variants.		Example
Entropy parameter: Piaggi-Parrinello fingerprint for distinguishing crystal structures.	Method	Example
Chemical short range order: Warren-Cowley parameters for multi-component alloys.		Example
Atomic deformation: atomic strain, von Mises invariant, \(D^2_{\min}\), slip vector.	Method	Example
Wigner-Seitz defect analysis: vacancies, interstitials, antisites against a reference.	Method	Example
ACE descriptors: Atomic Cluster Expansion features up to body order four.	Method	Example