DOE OSTI2020
MgSc8Cu29Ga15 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. Mg is bonded in a 3-coordinate geometry to three Sc, ten Cu, and one Ga atom. There are two shorter (3.00 Å) and one longer (3.04 Å) Mg–Sc bond lengths. There are a spread of Mg–Cu bond distances ranging from 2.48–3.26 Å. The Mg–Ga bond length is 2.91 Å. There are six inequivalent Sc sites. In the first Sc site, Sc is bonded in a 6-coordinate geometry to nine Cu and six Ga atoms. There are a spread of Sc–Cu bond distances ranging from 2.80–3.11 Å. There are a spread of Sc–Ga bond distances ranging from 2.93–3.30 Å. In the second Sc site, Sc is bonded in a 1-coordinate geometry to one Mg, eight Cu, and six Ga atoms. There are a spread of Sc–Cu bond distances ranging from 2.80–3.21 Å. There are a spread of Sc–Ga bond distances ranging from 2.85–3.15 Å. In the third Sc site, Sc is bonded in a 12-coordinate geometry to six Cu and eight Ga atoms. There are a spread of Sc–Cu bond distances ranging from 2.92–3.24 Å. There are a spread of Sc–Ga bond distances ranging from 2.89–2.95 Å. In the fourth Sc site, Sc is bonded in a 12-coordinate geometry to six Cu and eight Ga atoms. There are a spread of Sc–Cu bond distances ranging from 2.95–3.25 Å. There are a spread of Sc–Ga bond distances ranging from 2.89–2.94 Å. In the fifth Sc site, Sc is bonded in a 8-coordinate geometry to fifteen Cu and two equivalent Ga atoms. There are a spread of Sc–Cu bond distances ranging from 2.82–3.32 Å. Both Sc–Ga bond lengths are 2.87 Å. In the sixth Sc site, Sc is bonded in a 8-coordinate geometry to one Mg, fourteen Cu, and two equivalent Ga atoms. There are a spread of Sc–Cu bond distances ranging from 2.78–3.24 Å. Both Sc–Ga bond lengths are 2.86 Å. There are nineteen inequivalent Cu sites. In the first Cu site, Cu is bonded in a 12-coordinate geometry to three Sc, six Cu, and three Ga atoms. There are a spread of Cu–Cu bond distances ranging from 2.49–2.94 Å. There are a spread of Cu–Ga bond distances ranging from 2.57–2.98 Å. In the second Cu site, Cu is bonded in a 12-coordinate geometry to three Sc, six Cu, and three Ga atoms. There are a spread of Cu–Cu bond distances ranging from 2.49–2.90 Å. There are a spread of Cu–Ga bond distances ranging from 2.57–3.02 Å. In the third Cu site, Cu is bonded in a 12-coordinate geometry to three Sc, six Cu, and three Ga atoms. There are a spread of Cu–Cu bond distances ranging from 2.49–2.94 Å. There are a spread of Cu–Ga bond distances ranging from 2.56–2.99 Å. In the fourth Cu site, Cu is bonded in a 12-coordinate geometry to three Sc, six Cu, and three Ga atoms. There are a spread of Cu–Cu bond distances ranging from 2.53–3.00 Å. There are a spread of Cu–Ga bond distances ranging from 2.58–3.02 Å. In the fifth Cu site, Cu is bonded in a 12-coordinate geometry to three Sc, five Cu, and five Ga atoms. There are a spread of Cu–Cu bond distances ranging from 2.71–3.17 Å. There are a spread of Cu–Ga bond distances ranging from 2.51–2.71 Å. In the sixth Cu site, Cu is bonded in a 12-coordinate geometry to one Mg, three Sc, four Cu, and five Ga atoms. There are one shorter (2.66 Å) and one longer (2.68 Å) Cu–Cu bond lengths. There are a spread of Cu–Ga bond distances ranging from 2.55–2.73 Å. In the seventh Cu site, Cu is bonded in a 1-coordinate geometry to one Mg, three Sc, four Cu, and four Ga atoms. There are one shorter (2.55 Å) and one longer (3.04 Å) Cu–Cu bond lengths. There are a spread of Cu–Ga bond distances ranging from 2.51–2.67 Å. In the eighth Cu site, Cu is bonded in a 11-coordinate geometry to one Mg, three Sc, five Cu, and four Ga atoms. There are one shorter (2.46 Å) and one longer (2.52 Å) Cu–Cu bond lengths. There are a spread of Cu–Ga bond distances ranging from 2.57–2.78 Å. In the ninth Cu site, Cu is bonded in a 11-coordinate geometry to eleven Cu atoms. There are a spread of Cu–Cu bond distances ranging from 2.40–2.78 Å. In the tenth Cu site, Cu is bonded in a 11-coordinate geometry to eleven Cu atoms. There are a spread of Cu–Cu bond distances ranging from 2.41–2.53 Å. In the eleventh Cu site, Cu is bonded in a 8-coordinate geometry to seven Cu and two Ga atoms. The Cu–Cu bond length is 2.96 Å. There are one shorter (2.48 Å) and one longer (2.49 Å) Cu–Ga bond lengths. In the twelfth Cu site, Cu is bonded in a 1-coordinate geometry to three Sc, seven Cu, and one Ga atom. There are one shorter (2.92 Å) and one longer (3.04 Å) Cu–Cu bond lengths. The Cu–Ga bond length is 2.33 Å. In the thirteenth Cu site, Cu is bonded in a 11-coordinate geometry to one Mg, three Sc, six Cu, and one Ga atom. The Cu–Cu bond length is 2.85 Å. The Cu–Ga bond length is 2.33 Å. In the fourteenth Cu site, Cu is bonded in a 1-coordinate geometry to one Mg, three Sc, and seven Cu atoms. The Cu–Cu bond length is 2.95 Å. In the fifteenth Cu site, Cu is bonded in a 11-coordinate geometry to one Mg, three Sc, and seven Cu atoms. The Cu–Cu bond length is 2.49 Å. In the sixteenth Cu site, Cu is bonded in a 12-coordinate geometry to two Sc and ten Cu atoms. Both Cu–Cu bond lengths are 2.54 Å. In the seventeenth Cu site, Cu is bonded in a 12-coordinate geometry to two Sc and eight Cu atoms. Both Cu–Cu bond lengths are 2.54 Å. In the eighteenth Cu site, Cu is bonded in a 6-coordinate geometry to four Sc, seven Cu, and two Ga atoms. The Cu–Cu bond length is 2.73 Å. There are one shorter (2.45 Å) and one longer (2.48 Å) Cu–Ga bond lengths. In the nineteenth Cu site, Cu is bonded in a 8-coordinate geometry to one Mg, three Sc, seven Cu, and one Ga atom. The Cu–Ga bond length is 2.52 Å. There are thirteen inequivalent Ga sites. In the first Ga site, Ga is bonded to three Sc, four Cu, and five Ga atoms to form distorted GaSc3Ga5Cu4 cuboctahedra that share corners with three GaSc3Ga5Cu4 cuboctahedra, an edgeedge with one GaSc4Ga4Cu4 cuboctahedra, and faces with three GaSc3Ga5Cu4 cuboctahedra. There are a spread of Ga–Ga bond distances ranging from 2.47–2.78 Å. In the second Ga site, Ga is bonded to three Sc, four Cu, and five Ga atoms to form distorted GaSc3Ga5Cu4 cuboctahedra that share corners with three GaSc3Ga5Cu4 cuboctahedra, an edgeedge with one GaSc4Ga4Cu4 cuboctahedra, and faces with three GaSc3Ga5Cu4 cuboctahedra. There are a spread of Ga–Ga bond distances ranging from 2.47–2.80 Å. In the third Ga site, Ga is bonded to three Sc, four Cu, and five Ga atoms to form distorted GaSc3Ga5Cu4 cuboctahedra that share corners with three GaSc3Ga5Cu4 cuboctahedra, an edgeedge with one GaSc4Ga4Cu4 cuboctahedra, and faces with three GaSc3Ga5Cu4 cuboctahedra. There are a spread of Ga–Ga bond distances ranging from 2.47–2.70 Å. In the fourth Ga site, Ga is bonded to three Sc, four Cu, and five Ga atoms to form distorted GaSc3Ga5Cu4 cuboctahedra that share corners with three GaSc3Ga5Cu4 cuboctahedra, an edgeedge with one GaSc4Ga4Cu4 cuboctahedra, and faces with three GaSc3Ga5Cu4 cuboctahedra. There are a spread of Ga–Ga bond distances ranging from 2.47–2.76 Å. In the fifth Ga site, Ga is bonded in a 12-coordinate geometry to three Sc, five Cu, and four Ga atoms. There are one shorter (2.64 Å) and one longer (2.76 Å) Ga–Ga bond lengths. In the sixth Ga site, Ga is bonded in a 12-coordinate geometry to three Sc, five Cu, and four Ga atoms. There are one shorter (2.63 Å) and one longer (2.80 Å) Ga–Ga bond lengths. In the seventh Ga site, Ga is bonded in a 6-coordinate geometry to four Sc, six Cu, and three Ga atoms. The Ga–Ga bond length is 2.77 Å. In the eighth Ga site, Ga is bonded in a 6-coordinate geometry to four Sc, six Cu, and three Ga atoms. In the ninth Ga site, Ga is bonded to four Sc, four Cu, and four Ga atoms to form a mixture of corner, edge, and face-sharing GaSc4Ga4Cu4 cuboctahedra. There are one shorter (2.37 Å) and one longer (2.38 Å) Ga–Ga bond lengths. In the tenth Ga site, Ga is bonded to four Sc, four Cu, and four Ga atoms to form a mixture of corner, edge, and face-sharing GaSc4Ga4Cu4 cuboctahedra. Both Ga–Ga bond lengths are 2.38 Å. In the eleventh Ga site, Ga is bonded in a 12-coordinate geometry to two equivalent Sc, four Cu, and six Ga atoms. In the twelfth Ga site, Ga is bonded in a 12-coordinate geometry to two equivalent Sc, four Cu, and six Ga atoms. In the thirteenth Ga site, Ga is bonded in a distorted body-centered cubic geometry to one Mg and seven Cu atoms.