Mn4Al4C tau-carbide built from L1₀ prototype (P4/mmm) — prototype-substitution toy
.cifBuilt by prototype substitution (toy, projects/prototype-substitution): L1₀ MnAl fct sublattice (a=3.92, c=3.58 lit.) doubled along c with one C in the Al-plane 1d octahedral void (4 Al in-plane + 2 Mn axial, Vero 2023 model). Validation: parses, Mn4Al4C 9 sites ordered, SG P4/mmm @symprec 0.01, min pair dist 1.79 A (C–Mn axial), 12.2 A3/atom, 5.13 g/cm3. Note: same composition as GGen's I4/mmm Mn4Al4C candidate (file 09b14afd) but a different structural branch — that one has C in an all-Mn octahedron.