BiSI chalcohalide crystal structure, SbSI-type, Pnma (No. 62). Lattice: a=8.60, b=10.30, c=4.20 Å. Source: Nielsen et al., J. Mater. Chem. A, 2025 (lattice params derived from López et al. arxiv:2512.01531). Built from SbSI prototype ICSD coordinates.