Materials Data on Sm2Co17N2 by Materials Project

Abstract

Sm2Co17N2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Sm is bonded in a distorted bent 120 degrees geometry to nine Co and two equivalent N atoms. There are a spread of Sm–Co bond distances ranging from 2.98–3.40 Å. Both Sm–N bond lengths are 2.49 Å. There are seven inequivalent Co sites. In the first Co site, Co is bonded in a 2-coordinate geometry to one Sm and thirteen Co atoms. There are a spread of Co–Co bond distances ranging from 2.33–2.71 Å. In the second Co site, Co is bonded to three equivalent Sm and nine Co atoms to form distorted CoSm3Co9 cuboctahedra that share corners with eleven CoSm3Co9 cuboctahedra, corners with four equivalent NSm2Co4 octahedra, edges with four CoSm3Co9 cuboctahedra, faces with eight CoSm3Co9 cuboctahedra, and faces with two equivalent NSm2Co4 octahedra. The corner-sharing octahedra tilt angles range from 62–68°. There are a spread of Co–Co bond distances ranging from 2.41–2.58 Å. In the third Co site, Co is bonded in a single-bond geometry to five Co and one N atom. There are a spread of Co–Co bond distances ranging from 2.41–2.51 Å. The Co–N bond length is 1.84 Å. In the fourth Co site, Co is bonded to two equivalent Sm and ten Co atoms to form distorted CoSm2Co10 cuboctahedra that share corners with eight CoSm3Co9 cuboctahedra, corners with four equivalent NSm2Co4 octahedra, edges with three CoSm2Co10 cuboctahedra, edges with two equivalent NSm2Co4 octahedra, and faces with nine CoSm3Co9 cuboctahedra. The corner-sharing octahedra tilt angles range from 21–27°. There are two shorter (2.37 Å) and two longer (2.40 Å) Co–Co bond lengths. In the fifth Co site, Co is bonded in a single-bond geometry to six Co and one N atom. There are one shorter (2.37 Å) and one longer (2.39 Å) Co–Co bond lengths. The Co–N bond length is 1.85 Å. In the sixth Co site, Co is bonded to two equivalent Sm and ten Co atoms to form distorted CoSm2Co10 cuboctahedra that share corners with fourteen CoSm3Co9 cuboctahedra, edges with two equivalent CoSm3Co9 cuboctahedra, faces with ten CoSm3Co9 cuboctahedra, and faces with four equivalent NSm2Co4 octahedra. In the seventh Co site, Co is bonded to two equivalent Sm and ten Co atoms to form CoSm2Co10 cuboctahedra that share corners with eight CoSm3Co9 cuboctahedra, corners with two equivalent NSm2Co4 octahedra, edges with four CoSm2Co10 cuboctahedra, faces with eight CoSm3Co9 cuboctahedra, and faces with two equivalent NSm2Co4 octahedra. The corner-sharing octahedral tilt angles are 45°. N is bonded to two equivalent Sm and four Co atoms to form NSm2Co4 octahedra that share corners with ten CoSm3Co9 cuboctahedra, corners with two equivalent NSm2Co4 octahedra, edges with two equivalent CoSm2Co10 cuboctahedra, and faces with six CoSm2Co10 cuboctahedra. The corner-sharing octahedral tilt angles are 64°.