Materials Data on MgGa2 by Materials Project

MgGa2 crystallizes in the trigonal R32 space group. The structure is three-dimensional. there are three inequivalent Mg sites. In the first Mg site, Mg is bonded to three equivalent Mg and nine Ga atoms to form distorted MgMg3Ga9 cuboctahedra that share corners with six equivalent GaMg6Ga6 cuboctahedra, corners with twelve MgMg3Ga9 cuboctahedra, edges with six equivalent MgMg3Ga9 cuboctahedra, edges with twelve GaMg4Ga8 cuboctahedra, faces with four equivalent MgMg3Ga9 cuboctahedra, and faces with sixteen GaMg4Ga8 cuboctahedra. All Mg–Mg bond lengths are 3.02 Å. There are a spread of Mg–Ga bond distances ranging from 2.99–3.02 Å. In the second Mg site, Mg is bonded to three equivalent Mg and nine Ga atoms to form distorted MgMg3Ga9 cuboctahedra that share corners with six equivalent GaMg6Ga6 cuboctahedra, corners with twelve MgMg3Ga9 cuboctahedra, edges with six equivalent MgMg3Ga9 cuboctahedra, edges with twelve GaMg4Ga8 cuboctahedra, faces with four equivalent MgMg3Ga9 cuboctahedra, and faces with sixteen GaMg4Ga8 cuboctahedra. All Mg–Mg bond lengths are 3.02 Å. There are a spread of Mg–Ga bond distances ranging from 2.99–3.02 Å. In the third Mg site, Mg is bonded to three equivalent Mg and nine Ga atoms to form distorted MgMg3Ga9 cuboctahedra that share corners with six equivalent GaMg6Ga6 cuboctahedra, corners with twelve MgMg3Ga9 cuboctahedra, edges with six equivalent MgMg3Ga9 cuboctahedra, edges with twelve GaMg4Ga8 cuboctahedra, faces with four equivalent MgMg3Ga9 cuboctahedra, and faces with sixteen GaMg4Ga8 cuboctahedra. All Mg–Mg bond lengths are 3.02 Å. There are a spread of Mg–Ga bond distances ranging from 2.99–3.02 Å. There are seven inequivalent Ga sites. In the first Ga site, Ga is bonded to four Mg and eight Ga atoms to form distorted GaMg4Ga8 cuboctahedra that share corners with eighteen GaMg4Ga8 cuboctahedra, edges with eight MgMg3Ga9 cuboctahedra, edges with ten GaMg6Ga6 cuboctahedra, faces with eight MgMg3Ga9 cuboctahedra, and faces with twelve GaMg4Ga8 cuboctahedra. There are a spread of Ga–Ga bond distances ranging from 3.00–3.04 Å. In the second Ga site, Ga is bonded to four Mg and eight Ga atoms to form distorted GaMg4Ga8 cuboctahedra that share corners with eighteen GaMg4Ga8 cuboctahedra, edges with eight MgMg3Ga9 cuboctahedra, edges with ten GaMg6Ga6 cuboctahedra, faces with eight MgMg3Ga9 cuboctahedra, and faces with twelve GaMg4Ga8 cuboctahedra. There are a spread of Ga–Ga bond distances ranging from 3.00–3.04 Å. In the third Ga site, Ga is bonded to six equivalent Mg and six Ga atoms to form distorted GaMg6Ga6 cuboctahedra that share corners with six equivalent GaMg6Ga6 cuboctahedra, corners with twelve MgMg3Ga9 cuboctahedra, edges with eighteen GaMg4Ga8 cuboctahedra, faces with eight MgMg3Ga9 cuboctahedra, and faces with twelve GaMg4Ga8 cuboctahedra. Both Ga–Ga bond lengths are 3.00 Å. In the fourth Ga site, Ga is bonded to four Mg and eight Ga atoms to form distorted GaMg4Ga8 cuboctahedra that share corners with eighteen GaMg4Ga8 cuboctahedra, edges with eight MgMg3Ga9 cuboctahedra, edges with ten GaMg6Ga6 cuboctahedra, faces with eight MgMg3Ga9 cuboctahedra, and faces with twelve GaMg4Ga8 cuboctahedra. There are four shorter (3.02 Å) and two longer (3.04 Å) Ga–Ga bond lengths. In the fifth Ga site, Ga is bonded to four Mg and eight Ga atoms to form distorted GaMg4Ga8 cuboctahedra that share corners with eighteen GaMg4Ga8 cuboctahedra, edges with eight MgMg3Ga9 cuboctahedra, edges with ten GaMg6Ga6 cuboctahedra, faces with eight MgMg3Ga9 cuboctahedra, and faces with twelve GaMg4Ga8 cuboctahedra. There are two shorter (3.02 Å) and one longer (3.04 Å) Ga–Ga bond lengths. In the sixth Ga site, Ga is bonded to four Mg and eight Ga atoms to form distorted GaMg4Ga8 cuboctahedra that share corners with eighteen GaMg4Ga8 cuboctahedra, edges with eight MgMg3Ga9 cuboctahedra, edges with ten GaMg6Ga6 cuboctahedra, faces with eight MgMg3Ga9 cuboctahedra, and faces with twelve GaMg4Ga8 cuboctahedra. There are one shorter (2.99 Å) and one longer (3.01 Å) Ga–Mg bond lengths. There are a spread of Ga–Ga bond distances ranging from 3.00–3.04 Å. In the seventh Ga site, Ga is bonded to four Mg and eight Ga atoms to form distorted GaMg4Ga8 cuboctahedra that share corners with eighteen GaMg4Ga8 cuboctahedra, edges with eight MgMg3Ga9 cuboctahedra, edges with ten GaMg6Ga6 cuboctahedra, faces with eight MgMg3Ga9 cuboctahedra, and faces with twelve GaMg4Ga8 cuboctahedra. There are one shorter (2.99 Å) and one longer (3.01 Å) Ga–Mg bond lengths. There are a spread of Ga–Ga bond distances ranging from 3.00–3.04 Å.