Materials Data on RbMg6Sb by Materials Project

Abstract

RbMg6Sb crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Rb is bonded to ten Mg and two equivalent Sb atoms to form a mixture of face and corner-sharing RbMg10Sb2 cuboctahedra. There are a spread of Rb–Mg bond distances ranging from 3.49–3.58 Å. Both Rb–Sb bond lengths are 3.47 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Rb, three Mg, and two equivalent Sb atoms. There are two shorter (3.35 Å) and one longer (3.36 Å) Mg–Mg bond lengths. Both Mg–Sb bond lengths are 3.20 Å. In the second Mg site, Mg is bonded in a 10-coordinate geometry to two equivalent Rb and eight Mg atoms. There are four shorter (3.20 Å) and two longer (3.37 Å) Mg–Mg bond lengths. In the third Mg site, Mg is bonded in a 1-coordinate geometry to two equivalent Rb, two equivalent Mg, and one Sb atom. The Mg–Sb bond length is 3.02 Å. In the fourth Mg site, Mg is bonded in a 12-coordinate geometry to six Mg and two equivalent Sb atoms. Both Mg–Sb bond lengths are 3.53 Å. Sb is bonded in a 10-coordinate geometry to two equivalent Rb and eight Mg atoms.