Materials Data on MgGaCu by Materials Project

Abstract

MgCuGa is Hexagonal Laves-derived structured and crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to four Mg, seven Cu, and five Ga atoms. There are a spread of Mg–Mg bond distances ranging from 3.05–3.15 Å. There are a spread of Mg–Cu bond distances ranging from 2.96–3.05 Å. There are a spread of Mg–Ga bond distances ranging from 3.01–3.05 Å. In the second Mg site, Mg is bonded in a 12-coordinate geometry to three equivalent Mg, five Cu, and seven Ga atoms. There are two shorter (2.91 Å) and three longer (3.00 Å) Mg–Cu bond lengths. There are a spread of Mg–Ga bond distances ranging from 2.94–3.09 Å. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded to six Mg, two equivalent Cu, and four Ga atoms to form CuMg6Ga4Cu2 cuboctahedra that share corners with four equivalent CuMg6Ga2Cu4 cuboctahedra, corners with eight GaMg6Cu6 cuboctahedra, edges with six equivalent CuMg6Ga4Cu2 cuboctahedra, faces with eight CuMg6Ga4Cu2 cuboctahedra, and faces with twelve GaMg6Cu6 cuboctahedra. Both Cu–Cu bond lengths are 2.59 Å. There are two shorter (2.55 Å) and two longer (2.57 Å) Cu–Ga bond lengths. In the second Cu site, Cu is bonded to six Mg, four Cu, and two equivalent Ga atoms to form CuMg6Ga2Cu4 cuboctahedra that share corners with eight CuMg6Ga4Cu2 cuboctahedra, corners with ten GaMg6Ga4Cu2 cuboctahedra, edges with two equivalent CuMg6Ga2Cu4 cuboctahedra, edges with four equivalent GaMg6Ga4Cu2 cuboctahedra, faces with eight GaMg6Cu6 cuboctahedra, and faces with ten CuMg6Ga4Cu2 cuboctahedra. There are one shorter (2.57 Å) and one longer (2.62 Å) Cu–Cu bond lengths. There are one shorter (2.55 Å) and one longer (2.57 Å) Cu–Ga bond lengths. There are three inequivalent Ga sites. In the first Ga site, Ga is bonded to six Mg and six Cu atoms to form GaMg6Cu6 cuboctahedra that share corners with four equivalent CuMg6Ga4Cu2 cuboctahedra, corners with fourteen GaMg6Cu6 cuboctahedra, edges with six GaMg6Cu6 cuboctahedra, faces with four equivalent GaMg6Ga4Cu2 cuboctahedra, and faces with fourteen CuMg6Ga4Cu2 cuboctahedra. In the second Ga site, Ga is bonded to six Mg, two equivalent Cu, and four Ga atoms to form GaMg6Ga4Cu2 cuboctahedra that share corners with eight GaMg6Cu6 cuboctahedra, corners with ten CuMg6Ga4Cu2 cuboctahedra, edges with two equivalent GaMg6Ga4Cu2 cuboctahedra, edges with four equivalent CuMg6Ga2Cu4 cuboctahedra, faces with eight CuMg6Ga4Cu2 cuboctahedra, and faces with ten GaMg6Cu6 cuboctahedra. There are a spread of Ga–Ga bond distances ranging from 2.53–2.61 Å. In the third Ga site, Ga is bonded to six Mg, two equivalent Cu, and four equivalent Ga atoms to form GaMg6Ga4Cu2 cuboctahedra that share corners with six GaMg6Cu6 cuboctahedra, corners with twelve CuMg6Ga4Cu2 cuboctahedra, edges with six GaMg6Cu6 cuboctahedra, faces with eight equivalent GaMg6Ga4Cu2 cuboctahedra, and faces with ten CuMg6Ga4Cu2 cuboctahedra.