Materials Data on SrMg6W by Materials Project

Abstract

SrMg6W crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Sr is bonded to twelve Mg atoms to form SrMg12 cuboctahedra that share corners with four equivalent SrMg12 cuboctahedra, corners with eight equivalent WMg12 cuboctahedra, edges with eight equivalent MgSr2Mg8W2 cuboctahedra, faces with two equivalent SrMg12 cuboctahedra, faces with four equivalent MgSr2Mg8W2 cuboctahedra, and faces with four equivalent WMg12 cuboctahedra. There are a spread of Sr–Mg bond distances ranging from 3.24–3.41 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent Sr, eight Mg, and two equivalent W atoms to form distorted MgSr2Mg8W2 cuboctahedra that share corners with twelve equivalent MgSr2Mg8W2 cuboctahedra, edges with four equivalent SrMg12 cuboctahedra, edges with four equivalent WMg12 cuboctahedra, faces with two equivalent SrMg12 cuboctahedra, faces with two equivalent WMg12 cuboctahedra, and faces with six equivalent MgSr2Mg8W2 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.17–3.22 Å. There are one shorter (3.21 Å) and one longer (3.28 Å) Mg–W bond lengths. In the second Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Sr, six Mg, and two equivalent W atoms. There are one shorter (2.83 Å) and one longer (2.84 Å) Mg–Mg bond lengths. Both Mg–W bond lengths are 2.97 Å. In the third Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Sr, six Mg, and two equivalent W atoms. Both Mg–W bond lengths are 3.00 Å. In the fourth Mg site, Mg is bonded in a 2-coordinate geometry to two equivalent Sr, six Mg, and two equivalent W atoms. Both Mg–W bond lengths are 3.00 Å. W is bonded to twelve Mg atoms to form WMg12 cuboctahedra that share corners with four equivalent WMg12 cuboctahedra, corners with eight equivalent SrMg12 cuboctahedra, edges with eight equivalent MgSr2Mg8W2 cuboctahedra, faces with two equivalent WMg12 cuboctahedra, faces with four equivalent SrMg12 cuboctahedra, and faces with four equivalent MgSr2Mg8W2 cuboctahedra.