Materials Data on RbMg6B by Materials Project
RbMg6B crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Rb is bonded in a 12-coordinate geometry to two equivalent Rb and ten Mg atoms. Both Rb–Rb bond lengths are 3.42 Å. There are a spread of Rb–Mg bond distances ranging from 3.41–4.29 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a distorted L-shaped geometry to one Rb, three Mg, and two equivalent B atoms. There are two shorter (3.21 Å) and one longer (3.56 Å) Mg–Mg bond lengths. Both Mg–B bond lengths are 2.36 Å. In the second Mg site, Mg is bonded to two equivalent Rb and ten Mg atoms to form a mixture of distorted edge, corner, and face-sharing MgRb2Mg10 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.29–3.42 Å. In the third Mg site, Mg is bonded in a single-bond geometry to two equivalent Rb, three Mg, and one B atom. The Mg–Mg bond length is 3.41 Å. The Mg–B bond length is 2.42 Å. In the fourth Mg site, Mg is bonded to two equivalent Rb and ten Mg atoms to form a mixture of edge, corner, and face-sharing MgRb2Mg10 cuboctahedra. Both Mg–Mg bond lengths are 3.42 Å. B is bonded in a 6-coordinate geometry to six Mg atoms.