Materials Data on Fe12Ge3As2 by Materials Project
Fe12Ge3As2 crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are six inequivalent Fe sites. In the first Fe site, Fe is bonded in a 4-coordinate geometry to three equivalent Fe, two equivalent Ge, and two As atoms. There are a spread of Fe–Fe bond distances ranging from 2.49–2.91 Å. There are one shorter (2.41 Å) and one longer (2.52 Å) Fe–Ge bond lengths. There are one shorter (2.45 Å) and one longer (2.64 Å) Fe–As bond lengths. In the second Fe site, Fe is bonded in a 4-coordinate geometry to three equivalent Fe, two equivalent Ge, and two As atoms. There are a spread of Fe–Fe bond distances ranging from 2.49–2.90 Å. There are one shorter (2.41 Å) and one longer (2.52 Å) Fe–Ge bond lengths. There are one shorter (2.46 Å) and one longer (2.64 Å) Fe–As bond lengths. In the third Fe site, Fe is bonded in a 3-coordinate geometry to three equivalent Fe and three equivalent Ge atoms. All Fe–Fe bond lengths are 2.47 Å. All Fe–Ge bond lengths are 2.38 Å. In the fourth Fe site, Fe is bonded in a 3-coordinate geometry to three equivalent Fe and three equivalent Ge atoms. All Fe–Fe bond lengths are 2.47 Å. All Fe–Ge bond lengths are 2.38 Å. In the fifth Fe site, Fe is bonded in a trigonal bipyramidal geometry to three equivalent Ge and two As atoms. All Fe–Ge bond lengths are 2.38 Å. Both Fe–As bond lengths are 2.33 Å. In the sixth Fe site, Fe is bonded in a 2-coordinate geometry to ten Fe, two equivalent Ge, and two As atoms. Both Fe–Fe bond lengths are 2.84 Å. Both Fe–Ge bond lengths are 2.74 Å. Both Fe–As bond lengths are 2.68 Å. Ge is bonded in a 9-coordinate geometry to nine Fe atoms. There are two inequivalent As sites. In the first As site, As is bonded in a 10-coordinate geometry to ten Fe atoms. In the second As site, As is bonded in a 10-coordinate geometry to ten Fe atoms.