DOI: 10.17188/1745139
title: Materials Data on Sm2Fe15Si2 by Materials Project

description: Sm2Fe15Si2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are two inequivalent Sm sites. In the first Sm site, Sm is bonded in a 7-coordinate geometry to seventeen Fe and two equivalent Si atoms. There are a spread of Sm–Fe bond distances ranging from 2.99–3.27 Å. Both Sm–Si bond lengths are 3.13 Å. In the second Sm site, Sm is bonded in a 10-coordinate geometry to fifteen Fe and four equivalent Si atoms. There are a spread of Sm–Fe bond distances ranging from 2.99–3.26 Å. There are two shorter (3.19 Å) and two longer (3.21 Å) Sm–Si bond lengths. There are ten inequivalent Fe sites. In the first Fe site, Fe is bonded to two Sm, nine Fe, and one Si atom to form distorted FeSm2Fe9Si cuboctahedra that share corners with four equivalent SiSm3Fe9 cuboctahedra, corners with ten FeSm2Fe9Si cuboctahedra, edges with two equivalent SiSm3Fe9 cuboctahedra, edges with four FeSm3Fe9 cuboctahedra, faces with two equivalent SiSm3Fe9 cuboctahedra, and faces with eight FeSm2Fe9Si cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.42–2.62 Å. The Fe–Si bond length is 2.42 Å. In the second Fe site, Fe is bonded to two Sm, eight Fe, and two equivalent Si atoms to form distorted FeSm2Fe8Si2 cuboctahedra that share corners with two equivalent SiSm3Fe9 cuboctahedra, corners with twelve FeSm2Fe9Si cuboctahedra, edges with two equivalent SiSm3Fe9 cuboctahedra, edges with four FeSm3Fe9 cuboctahedra, faces with two equivalent SiSm3Fe9 cuboctahedra, and faces with eight FeSm2Fe9Si cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.44–2.63 Å. Both Fe–Si bond lengths are 2.41 Å. In the third Fe site, Fe is bonded in a 2-coordinate geometry to one Sm and thirteen Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.36–2.77 Å. In the fourth Fe site, Fe is bonded in a 4-coordinate geometry to one Sm, eleven Fe, and two equivalent Si atoms. There are a spread of Fe–Fe bond distances ranging from 2.65–2.78 Å. Both Fe–Si bond lengths are 2.60 Å. In the fifth Fe site, Fe is bonded in a 12-coordinate geometry to two Sm, nine Fe, and one Si atom. There are a spread of Fe–Fe bond distances ranging from 2.49–2.64 Å. The Fe–Si bond length is 2.63 Å. In the sixth Fe site, Fe is bonded in a 12-coordinate geometry to two Sm, nine Fe, and one Si atom. There are a spread of Fe–Fe bond distances ranging from 2.49–2.62 Å. The Fe–Si bond length is 2.52 Å. In the seventh Fe site, Fe is bonded in a 12-coordinate geometry to two Sm, eight Fe, and two equivalent Si atoms. There are a spread of Fe–Fe bond distances ranging from 2.49–2.65 Å. There are one shorter (2.52 Å) and one longer (2.61 Å) Fe–Si bond lengths. In the eighth Fe site, Fe is bonded to three Sm and nine Fe atoms to form FeSm3Fe9 cuboctahedra that share corners with fifteen FeSm2Fe9Si cuboctahedra, edges with four FeSm2Fe9Si cuboctahedra, edges with four equivalent SiSm3Fe9 cuboctahedra, faces with four equivalent SiSm3Fe9 cuboctahedra, and faces with six FeSm2Fe9Si cuboctahedra. Both Fe–Fe bond lengths are 2.46 Å. In the ninth Fe site, Fe is bonded to three Sm, eight Fe, and one Si atom to form FeSm3Fe8Si cuboctahedra that share corners with five equivalent SiSm3Fe9 cuboctahedra, corners with ten FeSm2Fe9Si cuboctahedra, an edgeedge with one SiSm3Fe9 cuboctahedra, edges with seven FeSm2Fe9Si cuboctahedra, faces with two equivalent SiSm3Fe9 cuboctahedra, and faces with eight FeSm2Fe9Si cuboctahedra. The Fe–Si bond length is 2.46 Å. In the tenth Fe site, Fe is bonded to three Sm, seven Fe, and two equivalent Si atoms to form distorted FeSm3Fe7Si2 cuboctahedra that share corners with six equivalent SiSm3Fe9 cuboctahedra, corners with nine FeSm2Fe9Si cuboctahedra, edges with eight FeSm2Fe9Si cuboctahedra, faces with two equivalent SiSm3Fe9 cuboctahedra, and faces with eight FeSm2Fe9Si cuboctahedra. Both Fe–Si bond lengths are 2.48 Å. Si is bonded to three Sm and nine Fe atoms to form distorted SiSm3Fe9 cuboctahedra that share corners with two equivalent SiSm3Fe9 cuboctahedra, corners with thirteen FeSm2Fe9Si cuboctahedra, edges with two equivalent SiSm3Fe9 cuboctahedra, edges with six FeSm2Fe9Si cuboctahedra, faces with two equivalent SiSm3Fe9 cuboctahedra, and faces with eight FeSm2Fe9Si cuboctahedra.