Materials Data on Nb6Ni7 by Materials Project

Abstract

Ni7Nb6 is Frank-Kasper $\mu$ Phase structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are three inequivalent Nb sites. In the first Nb site, Nb is bonded in a 6-coordinate geometry to nine Nb and six equivalent Ni atoms. There are a spread of Nb–Nb bond distances ranging from 2.83–3.13 Å. There are three shorter (2.74 Å) and three longer (2.83 Å) Nb–Ni bond lengths. In the second Nb site, Nb is bonded in a 6-coordinate geometry to four Nb and twelve Ni atoms. There are one shorter (2.81 Å) and three longer (2.89 Å) Nb–Nb bond lengths. There are a spread of Nb–Ni bond distances ranging from 2.71–2.99 Å. In the third Nb site, Nb is bonded in a 7-coordinate geometry to eight Nb and six equivalent Ni atoms. The Nb–Nb bond length is 2.61 Å. All Nb–Ni bond lengths are 2.68 Å. There are two inequivalent Ni sites. In the first Ni site, Ni is bonded to six equivalent Nb and six equivalent Ni atoms to form NiNb6Ni6 cuboctahedra that share corners with twelve equivalent NiNb7Ni5 cuboctahedra, edges with six equivalent NiNb6Ni6 cuboctahedra, and faces with eighteen equivalent NiNb7Ni5 cuboctahedra. All Ni–Ni bond lengths are 2.46 Å. In the second Ni site, Ni is bonded to seven Nb and five Ni atoms to form NiNb7Ni5 cuboctahedra that share corners with fifteen NiNb6Ni6 cuboctahedra, edges with five equivalent NiNb7Ni5 cuboctahedra, and faces with thirteen NiNb6Ni6 cuboctahedra. There are two shorter (2.44 Å) and two longer (2.45 Å) Ni–Ni bond lengths.