Materials Data on Tm2Fe15Si2 by Materials Project

Abstract

Tm2Fe15Si2 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Tm sites. In the first Tm site, Tm is bonded in a 6-coordinate geometry to eighteen Fe atoms. There are a spread of Tm–Fe bond distances ranging from 2.87–3.23 Å. In the second Tm site, Tm is bonded in a 8-coordinate geometry to eighteen Fe and two equivalent Si atoms. There are a spread of Tm–Fe bond distances ranging from 2.91–3.17 Å. Both Tm–Si bond lengths are 2.94 Å. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to two equivalent Tm, eight Fe, and two equivalent Si atoms to form distorted FeTm2Fe8Si2 cuboctahedra that share corners with fourteen FeTm2Fe8Si2 cuboctahedra, edges with six equivalent FeTm3Fe8Si cuboctahedra, and faces with ten FeTm2Fe8Si2 cuboctahedra. There are four shorter (2.40 Å) and four longer (2.46 Å) Fe–Fe bond lengths. Both Fe–Si bond lengths are 2.54 Å. In the second Fe site, Fe is bonded in a 12-coordinate geometry to two Tm, eight Fe, and two equivalent Si atoms. There are a spread of Fe–Fe bond distances ranging from 2.50–2.57 Å. Both Fe–Si bond lengths are 2.82 Å. In the third Fe site, Fe is bonded to three Tm, eight Fe, and one Si atom to form a mixture of distorted edge, corner, and face-sharing FeTm3Fe8Si cuboctahedra. Both Fe–Fe bond lengths are 2.40 Å. The Fe–Si bond length is 2.57 Å. Si is bonded in a 8-coordinate geometry to one Tm, twelve Fe, and one Si atom. The Si–Si bond length is 2.46 Å.