Materials Data on Mg6NbC by Materials Project
Mg6NbC crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 11-coordinate geometry to nine Mg and two equivalent Nb atoms. There are a spread of Mg–Mg bond distances ranging from 3.02–3.37 Å. There are one shorter (3.07 Å) and one longer (3.26 Å) Mg–Nb bond lengths. In the second Mg site, Mg is bonded in a 10-coordinate geometry to ten Mg atoms. There are four shorter (2.89 Å) and two longer (3.02 Å) Mg–Mg bond lengths. In the third Mg site, Mg is bonded in a single-bond geometry to six Mg and one C atom. The Mg–C bond length is 2.12 Å. In the fourth Mg site, Mg is bonded in a single-bond geometry to six Mg and one C atom. The Mg–C bond length is 2.21 Å. Nb is bonded in a linear geometry to four equivalent Mg and two equivalent C atoms. Both Nb–C bond lengths are 2.21 Å. C is bonded to three Mg and two equivalent Nb atoms to form corner-sharing CMg3Nb2 square pyramids.