msgjson documentation#
msgjson provides magnetic space group (MSG) operator tables for all 1651 commensurate Shubnikov groups and implements symmetry-analysis workflows for magnetic structures. The library is inspired by the k-SUBGROUPSMAG and MAXMAGN workflows from the Bilbao Crystallographic Server [1], and is designed to complement magnetic structure refinement in GSAS-II [2], FullProf [3], and Jana2020 [4].
Features#
Operator tables for all 1651 commensurate MSGs (types I–IV)
k-vector compatibility filtering with centering-aware reciprocal lattice
Site-symmetry moment basis via SVD null-space analysis
k-maximal MSG selection (
maximal_msgs) — implements the Bilbao MAXMAGN definition; returns one entry per conjugacy class plus its domain-related origin variants (MAXMAGN “alternatives (domain-related)”)Full subgroup lattice search (
subgroup_msgs) — controlled descent to lower symmetries including cross-parent-SG candidatesDirect MSG analysis for a known BNS number (
analyze_msg)Domain operator enumeration (
domain_operators)Magnetic orbit moments with full operator transformation (
orbit_moments)Magnetic structure factor \(|F_M|^2\) with optional form-factor scaling (
magnetic_structure_factors)Magnetic form factors \(\langle j_0 \rangle\) and \(\langle j_2 \rangle\) for 3d, 4d, and lanthanide/actinide ions (
form_factor,j0,j2)