DOE OSTI2020
Sm2Co14B crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. there are two inequivalent Sm sites. In the first Sm site, Sm is bonded in a 12-coordinate geometry to sixteen Co and two equivalent B atoms. There are a spread of Sm–Co bond distances ranging from 2.95–3.24 Å. Both Sm–B bond lengths are 3.10 Å. In the second Sm site, Sm is bonded in a 7-coordinate geometry to sixteen Co and one B atom. There are a spread of Sm–Co bond distances ranging from 2.95–3.30 Å. The Sm–B bond length is 2.82 Å. There are six inequivalent Co sites. In the first Co site, Co is bonded to two Sm and ten Co atoms to form a mixture of distorted corner, edge, and face-sharing CoSm2Co10 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.34–2.58 Å. In the second Co site, Co is bonded to four Sm and eight Co atoms to form a mixture of corner and face-sharing CoSm4Co8 cuboctahedra. All Co–Co bond lengths are 2.52 Å. In the third Co site, Co is bonded in a distorted L-shaped geometry to two equivalent Sm, four Co, and two equivalent B atoms. There are two shorter (2.42 Å) and two longer (2.70 Å) Co–Co bond lengths. Both Co–B bond lengths are 2.02 Å. In the fourth Co site, Co is bonded in a 2-coordinate geometry to two Sm and twelve Co atoms. There are a spread of Co–Co bond distances ranging from 2.59–2.72 Å. In the fifth Co site, Co is bonded in a distorted single-bond geometry to two Sm, seven Co, and one B atom. The Co–Co bond length is 2.51 Å. The Co–B bond length is 2.05 Å. In the sixth Co site, Co is bonded to three Sm and nine Co atoms to form distorted CoSm3Co9 cuboctahedra that share corners with fourteen CoSm2Co10 cuboctahedra, edges with three CoSm3Co9 cuboctahedra, and faces with twelve CoSm2Co10 cuboctahedra. The Co–Co bond length is 2.41 Å. B is bonded in a 6-coordinate geometry to three Sm and six Co atoms.