Materials Data on Sm2Fe15Si2 by Materials Project

Abstract

Sm2Fe15Si2 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Sm is bonded in a 10-coordinate geometry to eighteen Fe and one Si atom. There are a spread of Sm–Fe bond distances ranging from 2.99–3.29 Å. The Sm–Si bond length is 3.05 Å. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to two equivalent Sm, eight Fe, and two equivalent Si atoms to form a mixture of distorted edge, corner, and face-sharing FeSm2Fe8Si2 cuboctahedra. There are four shorter (2.40 Å) and four longer (2.44 Å) Fe–Fe bond lengths. Both Fe–Si bond lengths are 2.55 Å. In the second Fe site, Fe is bonded to two equivalent Sm, eight Fe, and two equivalent Si atoms to form a mixture of distorted edge, corner, and face-sharing FeSm2Fe8Si2 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.42–2.66 Å. Both Fe–Si bond lengths are 2.73 Å. In the third Fe site, Fe is bonded to three equivalent Sm, eight Fe, and one Si atom to form a mixture of edge, corner, and face-sharing FeSm3Fe8Si cuboctahedra. Both Fe–Fe bond lengths are 2.44 Å. The Fe–Si bond length is 2.56 Å. Si is bonded in a 7-coordinate geometry to one Sm, twelve Fe, and one Si atom. The Si–Si bond length is 2.55 Å.