Materials Data on Sm2Cr2Fe15C2 by Materials Project

Abstract

Sm2Cr2Fe15C2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Sm is bonded in a distorted bent 120 degrees geometry to one Cr, eight Fe, and two equivalent C atoms. The Sm–Cr bond length is 3.23 Å. There are a spread of Sm–Fe bond distances ranging from 3.04–3.40 Å. Both Sm–C bond lengths are 2.54 Å. Cr is bonded in a 1-coordinate geometry to one Sm, one Cr, and twelve Fe atoms. The Cr–Cr bond length is 2.15 Å. There are a spread of Cr–Fe bond distances ranging from 2.66–2.70 Å. There are six inequivalent Fe sites. In the first Fe site, Fe is bonded to two equivalent Sm, two equivalent Cr, and eight Fe atoms to form distorted FeSm2Cr2Fe8 cuboctahedra that share corners with eight FeSm2Cr2Fe8 cuboctahedra, corners with four equivalent CSm2Fe4 octahedra, edges with three FeSm2Cr2Fe8 cuboctahedra, edges with two equivalent CSm2Fe4 octahedra, and faces with nine FeSm2Cr2Fe8 cuboctahedra. The corner-sharing octahedra tilt angles range from 22–28°. There are a spread of Fe–Fe bond distances ranging from 2.44–2.67 Å. In the second Fe site, Fe is bonded in a single-bond geometry to two equivalent Cr, four Fe, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.43–2.57 Å. The Fe–C bond length is 1.85 Å. In the third Fe site, Fe is bonded in a single-bond geometry to one Cr, four Fe, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.45–2.57 Å. The Fe–C bond length is 1.92 Å. In the fourth Fe site, Fe is bonded to three equivalent Sm, one Cr, and eight Fe atoms to form distorted FeSm3CrFe8 cuboctahedra that share corners with eleven FeSm2Cr2Fe8 cuboctahedra, corners with four equivalent CSm2Fe4 octahedra, edges with four FeSm3CrFe8 cuboctahedra, faces with eight FeSm2Cr2Fe8 cuboctahedra, and faces with two equivalent CSm2Fe4 octahedra. The corner-sharing octahedra tilt angles range from 62–69°. Both Fe–Fe bond lengths are 2.47 Å. In the fifth Fe site, Fe is bonded to two equivalent Sm, two equivalent Cr, and eight Fe atoms to form distorted FeSm2Cr2Fe8 cuboctahedra that share corners with fourteen FeSm2Cr2Fe8 cuboctahedra, edges with two equivalent FeSm3CrFe8 cuboctahedra, faces with ten FeSm2Cr2Fe8 cuboctahedra, and faces with four equivalent CSm2Fe4 octahedra. In the sixth Fe site, Fe is bonded to two equivalent Sm, two equivalent Cr, and eight Fe atoms to form distorted FeSm2Cr2Fe8 cuboctahedra that share corners with eight FeSm2Cr2Fe8 cuboctahedra, corners with two equivalent CSm2Fe4 octahedra, edges with four FeSm2Cr2Fe8 cuboctahedra, faces with eight FeSm2Cr2Fe8 cuboctahedra, and faces with two equivalent CSm2Fe4 octahedra. The corner-sharing octahedral tilt angles are 46°. C is bonded to two equivalent Sm and four Fe atoms to form CSm2Fe4 octahedra that share corners with ten FeSm2Cr2Fe8 cuboctahedra, corners with two equivalent CSm2Fe4 octahedra, edges with two equivalent FeSm2Cr2Fe8 cuboctahedra, and faces with six FeSm2Cr2Fe8 cuboctahedra. The corner-sharing octahedral tilt angles are 63°.