tau-MnAlC literature structure (P4/mmm, 9 atoms, C in Al-plane 1d void)
.cifLiterature tau-carbide structure for Mn4Al4C (= MnAlC), built from the Vero et al. 2023 model (JAP 134, 153902): L10 sublattice, C at the 1d interstitial void in the Al plane (4 Al in-plane + 2 Mn axial coordination). 9-atom P4/mmm cell, 2x2x1 supercell of L10 tP2 MnAl (a=2.792, c=3.584). Validated: P4/mmm at symprec 0.01/0.1, Mn4Al4C, 9 sites, density 5.05 g/cm3, dmin 1.79 A (C-Mn axial). Built to close the structure-level blind spot in the SMACT-Crystalite funnel (random CSP landed on a 3-atom P4mm cell for this composition).