Materials Data on NaMg6W by Materials Project

Abstract

NaMg6W crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Na is bonded to ten Mg and two equivalent W atoms to form NaMg10W2 cuboctahedra that share corners with four equivalent MgNa2Mg10 cuboctahedra, corners with six equivalent NaMg10W2 cuboctahedra, edges with two equivalent MgNa2Mg10 cuboctahedra, edges with four equivalent WNa2Mg10 cuboctahedra, faces with two equivalent NaMg10W2 cuboctahedra, faces with two equivalent MgNa2Mg10 cuboctahedra, and faces with two equivalent WNa2Mg10 cuboctahedra. There are a spread of Na–Mg bond distances ranging from 2.97–3.27 Å. Both Na–W bond lengths are 3.18 Å. There are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to two equivalent Na, eight Mg, and two equivalent W atoms. There are a spread of Mg–Mg bond distances ranging from 2.88–3.40 Å. Both Mg–W bond lengths are 2.97 Å. In the second Mg site, Mg is bonded to two equivalent Na and ten Mg atoms to form MgNa2Mg10 cuboctahedra that share corners with four equivalent NaMg10W2 cuboctahedra, corners with six equivalent MgNa2Mg10 cuboctahedra, edges with two equivalent NaMg10W2 cuboctahedra, faces with two equivalent NaMg10W2 cuboctahedra, faces with two equivalent MgNa2Mg10 cuboctahedra, and faces with six equivalent WNa2Mg10 cuboctahedra. There are four shorter (3.10 Å) and two longer (3.12 Å) Mg–Mg bond lengths. In the third Mg site, Mg is bonded in a 12-coordinate geometry to two equivalent Na, four Mg, and two equivalent W atoms. There are one shorter (2.99 Å) and one longer (3.25 Å) Mg–W bond lengths. In the fourth Mg site, Mg is bonded in a distorted linear geometry to six Mg and two equivalent W atoms. Both Mg–W bond lengths are 3.14 Å. W is bonded to two equivalent Na and ten Mg atoms to form WNa2Mg10 cuboctahedra that share corners with six equivalent WNa2Mg10 cuboctahedra, edges with four equivalent NaMg10W2 cuboctahedra, faces with two equivalent NaMg10W2 cuboctahedra, faces with two equivalent WNa2Mg10 cuboctahedra, and faces with six equivalent MgNa2Mg10 cuboctahedra.