Materials Data on Tb2Fe4Si9 by Materials Project
Tb2Fe4Si9 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Tb4+ is bonded in a 6-coordinate geometry to eight Si+2.22- atoms. There are a spread of Tb–Si bond distances ranging from 2.88–3.19 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded in a 10-coordinate geometry to ten Si+2.22- atoms. There are a spread of Fe–Si bond distances ranging from 2.31–2.69 Å. In the second Fe3+ site, Fe3+ is bonded to seven Si+2.22- atoms to form distorted edge-sharing FeSi7 hexagonal pyramids. There are a spread of Fe–Si bond distances ranging from 2.31–2.47 Å. There are five inequivalent Si+2.22- sites. In the first Si+2.22- site, Si+2.22- is bonded in a 11-coordinate geometry to one Tb4+, four equivalent Fe3+, and six Si+2.22- atoms. There are three shorter (2.51 Å) and three longer (2.65 Å) Si–Si bond lengths. In the second Si+2.22- site, Si+2.22- is bonded in a 4-coordinate geometry to one Tb4+, four equivalent Fe3+, and six Si+2.22- atoms. There are three shorter (2.65 Å) and three longer (2.67 Å) Si–Si bond lengths. In the third Si+2.22- site, Si+2.22- is bonded in a 10-coordinate geometry to three equivalent Tb4+, three equivalent Fe3+, and four Si+2.22- atoms. The Si–Si bond length is 2.39 Å. In the fourth Si+2.22- site, Si+2.22- is bonded in a 6-coordinate geometry to three equivalent Tb4+, three equivalent Fe3+, and three equivalent Si+2.22- atoms. In the fifth Si+2.22- site, Si+2.22- is bonded in a 8-coordinate geometry to six equivalent Fe3+ and eight Si+2.22- atoms.