Materials Data on RbMg6C by Materials Project
RbMg6C crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Rb is bonded in a 8-coordinate geometry to two equivalent Rb and six Mg atoms. Both Rb–Rb bond lengths are 3.42 Å. There are two shorter (3.71 Å) and four longer (4.05 Å) Rb–Mg bond lengths. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a single-bond geometry to four Mg and one C atom. There are two shorter (3.11 Å) and two longer (3.40 Å) Mg–Mg bond lengths. The Mg–C bond length is 2.33 Å. In the second Mg site, Mg is bonded in a water-like geometry to two equivalent Rb and two equivalent C atoms. Both Mg–C bond lengths are 2.28 Å. In the third Mg site, Mg is bonded in a 10-coordinate geometry to two equivalent Rb and eight Mg atoms. There are two shorter (2.93 Å) and two longer (3.42 Å) Mg–Mg bond lengths. In the fourth Mg site, Mg is bonded in a 2-coordinate geometry to eight Mg atoms. Both Mg–Mg bond lengths are 3.42 Å. C is bonded to six Mg atoms to form distorted edge-sharing CMg6 pentagonal pyramids.