DOE OSTI2020
Sm2(CoNi)5 crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. there are two inequivalent Sm sites. In the first Sm site, Sm is bonded in a 6-coordinate geometry to six Co and twelve Ni atoms. There are four shorter (2.85 Å) and two longer (2.88 Å) Sm–Co bond lengths. All Sm–Ni bond lengths are 3.17 Å. In the second Sm site, Sm is bonded in a 6-coordinate geometry to ten Co and eight equivalent Ni atoms. There are six shorter (2.84 Å) and four longer (3.17 Å) Sm–Co bond lengths. All Sm–Ni bond lengths are 3.16 Å. There are three inequivalent Co sites. In the first Co site, Co is bonded in a 12-coordinate geometry to three Sm, two equivalent Co, and four equivalent Ni atoms. Both Co–Co bond lengths are 2.42 Å. All Co–Ni bond lengths are 2.45 Å. In the second Co site, Co is bonded in a 12-coordinate geometry to three Sm and six Ni atoms. All Co–Ni bond lengths are 2.44 Å. In the third Co site, Co is bonded to four equivalent Sm, four equivalent Co, and four equivalent Ni atoms to form CoSm4Co4Ni4 cuboctahedra that share corners with four equivalent CoSm4Co4Ni4 cuboctahedra, corners with twelve NiSm4Co5Ni3 cuboctahedra, edges with two equivalent CoSm4Co4Ni4 cuboctahedra, edges with eight equivalent NiSm4Co5Ni3 cuboctahedra, faces with two equivalent CoSm4Co4Ni4 cuboctahedra, and faces with eight equivalent NiSm4Co5Ni3 cuboctahedra. All Co–Ni bond lengths are 2.47 Å. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded to four equivalent Sm, four equivalent Co, and four equivalent Ni atoms to form NiSm4Co4Ni4 cuboctahedra that share corners with four equivalent CoSm4Co4Ni4 cuboctahedra, corners with twelve NiSm4Co5Ni3 cuboctahedra, edges with ten NiSm4Co5Ni3 cuboctahedra, and faces with ten NiSm4Co4Ni4 cuboctahedra. All Ni–Ni bond lengths are 2.47 Å. In the second Ni site, Ni is bonded to four Sm, five Co, and three Ni atoms to form NiSm4Co5Ni3 cuboctahedra that share corners with two equivalent CoSm4Co4Ni4 cuboctahedra, corners with fourteen NiSm4Co4Ni4 cuboctahedra, edges with two equivalent CoSm4Co4Ni4 cuboctahedra, edges with eight NiSm4Co4Ni4 cuboctahedra, faces with two equivalent CoSm4Co4Ni4 cuboctahedra, and faces with eight NiSm4Co4Ni4 cuboctahedra. There are one shorter (2.47 Å) and one longer (2.48 Å) Ni–Ni bond lengths.