DOI: 10.17188/1687530
title: Materials Data on Sm2Fe20Si2C by Materials Project

description: Sm2Fe20Si2C crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Sm is bonded in a distorted single-bond geometry to sixteen Fe and one C atom. There are a spread of Sm–Fe bond distances ranging from 3.06–3.46 Å. The Sm–C bond length is 2.64 Å. There are eleven inequivalent Fe sites. In the first Fe site, Fe is bonded in a single-bond geometry to eight Fe and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.41–2.72 Å. The Fe–C bond length is 1.85 Å. In the second Fe site, Fe is bonded in a single-bond geometry to seven Fe, one Si, and one C atom. There are a spread of Fe–Fe bond distances ranging from 2.38–2.67 Å. The Fe–Si bond length is 2.39 Å. The Fe–C bond length is 1.86 Å. In the third Fe site, Fe is bonded to two equivalent Sm and ten Fe atoms to form distorted FeSm2Fe10 cuboctahedra that share corners with three FeSm2Fe10 cuboctahedra, corners with two equivalent CSm2Fe4 octahedra, an edgeedge with one FeSm2Fe10 cuboctahedra, an edgeedge with one CSm2Fe4 octahedra, and faces with three FeSm2Fe10 cuboctahedra. The corner-sharing octahedra tilt angles range from 28–70°. There are a spread of Fe–Fe bond distances ranging from 2.42–2.73 Å. In the fourth Fe site, Fe is bonded in a 12-coordinate geometry to two equivalent Sm, nine Fe, and one Si atom. There are a spread of Fe–Fe bond distances ranging from 2.46–2.76 Å. The Fe–Si bond length is 2.41 Å. In the fifth Fe site, Fe is bonded in a 12-coordinate geometry to two equivalent Sm, nine Fe, and one Si atom. There are a spread of Fe–Fe bond distances ranging from 2.48–2.72 Å. The Fe–Si bond length is 2.44 Å. In the sixth Fe site, Fe is bonded in a 12-coordinate geometry to two equivalent Sm, eight Fe, and two Si atoms. There are a spread of Fe–Fe bond distances ranging from 2.47–2.68 Å. There are one shorter (2.41 Å) and one longer (2.44 Å) Fe–Si bond lengths. In the seventh Fe site, Fe is bonded in a 12-coordinate geometry to two equivalent Sm, nine Fe, and one Si atom. There are a spread of Fe–Fe bond distances ranging from 2.39–2.64 Å. The Fe–Si bond length is 2.39 Å. In the eighth Fe site, Fe is bonded in a 12-coordinate geometry to two equivalent Sm, eight Fe, and two Si atoms. The Fe–Fe bond length is 2.64 Å. There are one shorter (2.39 Å) and one longer (2.41 Å) Fe–Si bond lengths. In the ninth Fe site, Fe is bonded in a 3-coordinate geometry to two equivalent Sm, ten Fe, and two Si atoms. There are one shorter (2.63 Å) and one longer (2.69 Å) Fe–Fe bond lengths. There are one shorter (2.59 Å) and one longer (2.65 Å) Fe–Si bond lengths. In the tenth Fe site, Fe is bonded to two equivalent Sm and ten Fe atoms to form distorted FeSm2Fe10 cuboctahedra that share corners with four FeSm2Fe10 cuboctahedra, faces with four FeSm2Fe10 cuboctahedra, and faces with two equivalent CSm2Fe4 octahedra. In the eleventh Fe site, Fe is bonded to two equivalent Sm and ten Fe atoms to form distorted FeSm2Fe10 cuboctahedra that share corners with two equivalent FeSm2Fe10 cuboctahedra, edges with two equivalent FeSm2Fe10 cuboctahedra, edges with two equivalent CSm2Fe4 octahedra, and faces with four FeSm2Fe10 cuboctahedra. There are two inequivalent Si sites. In the first Si site, Si is bonded in a 10-coordinate geometry to ten Fe atoms. In the second Si site, Si is bonded in a 10-coordinate geometry to ten Fe atoms. C is bonded to two equivalent Sm and four Fe atoms to form CSm2Fe4 octahedra that share corners with four equivalent FeSm2Fe10 cuboctahedra, edges with four FeSm2Fe10 cuboctahedra, and faces with two equivalent FeSm2Fe10 cuboctahedra.