Materials Data on BaMg6C by Materials Project
BaMg6C crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Ba is bonded to two equivalent Ba and ten Mg atoms to form a mixture of distorted face, edge, and corner-sharing BaBa2Mg10 cuboctahedra. Both Ba–Ba bond lengths are 3.67 Å. There are a spread of Ba–Mg bond distances ranging from 3.52–4.18 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a single-bond geometry to two equivalent Mg and one C atom. Both Mg–Mg bond lengths are 3.05 Å. The Mg–C bond length is 2.30 Å. In the second Mg site, Mg is bonded in a water-like geometry to two equivalent Ba and two equivalent C atoms. Both Mg–C bond lengths are 2.32 Å. In the third Mg site, Mg is bonded in a 8-coordinate geometry to two equivalent Ba and six Mg atoms. Both Mg–Mg bond lengths are 2.94 Å. In the fourth Mg site, Mg is bonded in a 2-coordinate geometry to four equivalent Ba and two equivalent Mg atoms. C is bonded in a 6-coordinate geometry to six Mg atoms.