Materials Data on Er2Fe4Si9 by Materials Project

Er2Fe4Si9 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Er is bonded in a 6-coordinate geometry to three equivalent Fe and eight Si atoms. All Er–Fe bond lengths are 3.18 Å. There are a spread of Er–Si bond distances ranging from 2.85–3.16 Å. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded in a 7-coordinate geometry to ten Si atoms. There are a spread of Fe–Si bond distances ranging from 2.31–2.69 Å. In the second Fe site, Fe is bonded in a 10-coordinate geometry to three equivalent Er and seven Si atoms. There are a spread of Fe–Si bond distances ranging from 2.31–2.46 Å. There are five inequivalent Si sites. In the first Si site, Si is bonded in a 11-coordinate geometry to one Er, four equivalent Fe, and six Si atoms. There are three shorter (2.50 Å) and three longer (2.66 Å) Si–Si bond lengths. In the second Si site, Si is bonded in a 4-coordinate geometry to one Er, four equivalent Fe, and six Si atoms. There are three shorter (2.65 Å) and three longer (2.66 Å) Si–Si bond lengths. In the third Si site, Si is bonded in a 10-coordinate geometry to three equivalent Er, three equivalent Fe, and four Si atoms. The Si–Si bond length is 2.41 Å. In the fourth Si site, Si is bonded in a 6-coordinate geometry to three equivalent Er, three equivalent Fe, and three equivalent Si atoms. In the fifth Si site, Si is bonded in a 8-coordinate geometry to six equivalent Fe and eight Si atoms.