DOI: 10.17188/1695898
title: Materials Data on Nb9Fe3Ge2 by Materials Project

description: Nb9Fe3Ge2 is beta Uranium-derived structured and crystallizes in the orthorhombic Fmmm space group. The structure is three-dimensional. there are five inequivalent Nb sites. In the first Nb site, Nb is bonded in a 6-coordinate geometry to ten Nb, two equivalent Fe, and two equivalent Ge atoms. There are a spread of Nb–Nb bond distances ranging from 2.46–3.19 Å. Both Nb–Fe bond lengths are 2.84 Å. Both Nb–Ge bond lengths are 2.81 Å. In the second Nb site, Nb is bonded in a 1-coordinate geometry to four Nb, three Fe, and one Ge atom. There are a spread of Nb–Nb bond distances ranging from 2.71–3.07 Å. All Nb–Fe bond lengths are 2.72 Å. The Nb–Ge bond length is 2.60 Å. In the third Nb site, Nb is bonded in a 1-coordinate geometry to four Nb, two equivalent Fe, and two Ge atoms. There are a spread of Nb–Nb bond distances ranging from 2.76–3.07 Å. Both Nb–Fe bond lengths are 2.73 Å. There are one shorter (2.56 Å) and one longer (2.78 Å) Nb–Ge bond lengths. In the fourth Nb site, Nb is bonded in a 7-coordinate geometry to nine Nb, four Fe, and one Ge atom. There are one shorter (2.60 Å) and two longer (3.12 Å) Nb–Nb bond lengths. There are two shorter (2.82 Å) and two longer (2.84 Å) Nb–Fe bond lengths. The Nb–Ge bond length is 2.86 Å. In the fifth Nb site, Nb is bonded in a 7-coordinate geometry to nine Nb, three Fe, and two equivalent Ge atoms. The Nb–Nb bond length is 2.66 Å. There are two shorter (2.84 Å) and one longer (2.89 Å) Nb–Fe bond lengths. Both Nb–Ge bond lengths are 2.85 Å. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to ten Nb and two equivalent Fe atoms to form FeNb10Fe2 cuboctahedra that share corners with six FeNb10Fe2 cuboctahedra, corners with two equivalent GeNb4Ge2 octahedra, edges with three equivalent FeNb10Fe2 cuboctahedra, faces with four equivalent FeNb8Fe4 cuboctahedra, and faces with four equivalent GeNb10Fe2 cuboctahedra. The corner-sharing octahedral tilt angles are 16°. Both Fe–Fe bond lengths are 2.54 Å. In the second Fe site, Fe is bonded to eight Nb and four Fe atoms to form FeNb8Fe4 cuboctahedra that share corners with two equivalent FeNb8Fe4 cuboctahedra, corners with four equivalent GeNb10Fe2 cuboctahedra, corners with four equivalent GeNb4Ge2 octahedra, and faces with six FeNb10Fe2 cuboctahedra. The corner-sharing octahedral tilt angles are 43°. Both Fe–Fe bond lengths are 2.52 Å. In the third Fe site, Fe is bonded to eight Nb, two equivalent Fe, and two equivalent Ge atoms to form FeNb8Fe2Ge2 cuboctahedra that share corners with six FeNb10Fe2 cuboctahedra, corners with four equivalent GeNb4Ge2 octahedra, faces with two equivalent FeNb8Fe2Ge2 cuboctahedra, and faces with four equivalent GeNb10Fe2 cuboctahedra. The corner-sharing octahedral tilt angles are 43°. Both Fe–Fe bond lengths are 2.52 Å. Both Fe–Ge bond lengths are 2.61 Å. There are two inequivalent Ge sites. In the first Ge site, Ge is bonded to four Nb and two equivalent Ge atoms to form distorted GeNb4Ge2 octahedra that share corners with two equivalent GeNb10Fe2 cuboctahedra, corners with ten FeNb10Fe2 cuboctahedra, and corners with two equivalent GeNb4Ge2 octahedra. The corner-sharing octahedral tilt angles are 0°. Both Ge–Ge bond lengths are 2.52 Å. In the second Ge site, Ge is bonded to ten Nb and two equivalent Fe atoms to form GeNb10Fe2 cuboctahedra that share corners with two equivalent GeNb10Fe2 cuboctahedra, corners with four equivalent FeNb8Fe4 cuboctahedra, corners with two equivalent GeNb4Ge2 octahedra, edges with three equivalent GeNb10Fe2 cuboctahedra, and faces with eight FeNb10Fe2 cuboctahedra. The corner-sharing octahedral tilt angles are 17°.