Materials Data on Sm2Mn2Fe15 by Materials Project
Sm2Mn2Fe15 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Sm is bonded in a 9-coordinate geometry to one Mn and eighteen Fe atoms. The Sm–Mn bond length is 3.10 Å. There are a spread of Sm–Fe bond distances ranging from 3.04–3.30 Å. Mn is bonded in a 6-coordinate geometry to one Sm, one Mn, and twelve Fe atoms. The Mn–Mn bond length is 2.36 Å. There are six shorter (2.60 Å) and six longer (2.71 Å) Mn–Fe bond lengths. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to two equivalent Sm, two equivalent Mn, and eight Fe atoms to form distorted FeSm2Mn2Fe8 cuboctahedra that share corners with twenty-two FeSm2Mn2Fe8 cuboctahedra, edges with ten FeSm3MnFe8 cuboctahedra, and faces with eighteen FeSm2Mn2Fe8 cuboctahedra. There are four shorter (2.42 Å) and four longer (2.43 Å) Fe–Fe bond lengths. In the second Fe site, Fe is bonded to two equivalent Sm, two equivalent Mn, and eight Fe atoms to form a mixture of distorted corner, edge, and face-sharing FeSm2Mn2Fe8 cuboctahedra. There are a spread of Fe–Fe bond distances ranging from 2.44–2.65 Å. In the third Fe site, Fe is bonded to three equivalent Sm, one Mn, and eight Fe atoms to form a mixture of distorted corner, edge, and face-sharing FeSm3MnFe8 cuboctahedra. Both Fe–Fe bond lengths are 2.49 Å.