Materials Data on NbFe by Materials Project

Abstract

FeNb is Frank-Kasper $\mu$ Phase-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are seven inequivalent Nb sites. In the first Nb site, Nb is bonded in a 10-coordinate geometry to seven Nb and nine equivalent Fe atoms. There are a spread of Nb–Nb bond distances ranging from 2.80–2.96 Å. There are three shorter (2.90 Å) and six longer (3.00 Å) Nb–Fe bond lengths. In the second Nb site, Nb is bonded in a 6-coordinate geometry to four Nb and twelve Fe atoms. There are one shorter (2.72 Å) and three longer (2.95 Å) Nb–Nb bond lengths. There are a spread of Nb–Fe bond distances ranging from 2.76–2.93 Å. In the third Nb site, Nb is bonded in a 8-coordinate geometry to eight Nb and six equivalent Fe atoms. There are one shorter (2.64 Å) and six longer (3.14 Å) Nb–Nb bond lengths. All Nb–Fe bond lengths are 2.69 Å. In the fourth Nb site, Nb is bonded in a 8-coordinate geometry to eight Nb and six equivalent Fe atoms. All Nb–Nb bond lengths are 3.13 Å. All Nb–Fe bond lengths are 2.71 Å. In the fifth Nb site, Nb is bonded in a 6-coordinate geometry to nine Nb and six Fe atoms. All Nb–Nb bond lengths are 2.84 Å. All Nb–Fe bond lengths are 2.82 Å. In the sixth Nb site, Nb is bonded in a 6-coordinate geometry to nine Nb and six Fe atoms. There are three shorter (2.78 Å) and three longer (2.83 Å) Nb–Fe bond lengths. In the seventh Nb site, Nb is bonded to six equivalent Nb and six equivalent Fe atoms to form distorted NbNb6Fe6 cuboctahedra that share corners with twelve equivalent FeNb8Fe4 cuboctahedra, edges with six equivalent NbNb6Fe6 cuboctahedra, and faces with eighteen equivalent FeNb8Fe4 cuboctahedra. All Nb–Fe bond lengths are 2.57 Å. There are three inequivalent Fe sites. In the first Fe site, Fe is bonded to seven Nb and five Fe atoms to form FeNb7Fe5 cuboctahedra that share corners with fifteen FeNb7Fe5 cuboctahedra, edges with five FeNb8Fe4 cuboctahedra, and faces with thirteen FeNb7Fe5 cuboctahedra. There are one shorter (2.44 Å) and four longer (2.46 Å) Fe–Fe bond lengths. In the second Fe site, Fe is bonded to eight Nb and four equivalent Fe atoms to form distorted FeNb8Fe4 cuboctahedra that share corners with two equivalent NbNb6Fe6 cuboctahedra, corners with thirteen FeNb7Fe5 cuboctahedra, edges with five FeNb8Fe4 cuboctahedra, faces with three equivalent NbNb6Fe6 cuboctahedra, and faces with ten equivalent FeNb8Fe4 cuboctahedra. There are two shorter (2.41 Å) and two longer (2.52 Å) Fe–Fe bond lengths. In the third Fe site, Fe is bonded to six equivalent Nb and six equivalent Fe atoms to form FeNb6Fe6 cuboctahedra that share corners with twelve equivalent FeNb7Fe5 cuboctahedra, edges with six equivalent FeNb6Fe6 cuboctahedra, and faces with eighteen equivalent FeNb7Fe5 cuboctahedra.