Title: Materials Data on Nb4Si7Ni4 by Materials Project

Abstract

Nb4Ni4Si7 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Nb2+ sites. In the first Nb2+ site, Nb2+ is bonded to seven Si+1.71- atoms to form NbSi7 pentagonal bipyramids that share corners with eight equivalent NiSi6 octahedra, corners with eight NbSi7 pentagonal bipyramids, edges with three equivalent NbSi7 pentagonal bipyramids, faces with four equivalent NiSi6 octahedra, and faces with six NbSi7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 41–51°. There are a spread of Nb–Si bond distances ranging from 2.62–2.83 Å. In the second Nb2+ site, Nb2+ is bonded to seven Si+1.71- atoms to form NbSi7 pentagonal bipyramids that share corners with eight equivalent NiSi6 octahedra, corners with eight NbSi7 pentagonal bipyramids, an edgeedge with one NbSi7 pentagonal bipyramid, faces with four equivalent NiSi6 octahedra, and faces with six NbSi7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 41–52°. There are a spread of Nb–Si bond distances ranging from 2.64–2.81 Å. Ni1+ is bonded to six Si+1.71- atoms to form distorted NiSi6 octahedra that share corners with six equivalent NiSi6 octahedra, corners with eight NbSi7 pentagonal bipyramids, edges with three equivalent NiSi6 octahedra, faces with two equivalent NiSi6 octahedra, and facesmore » with four NbSi7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 34–38°. There are a spread of Ni–Si bond distances ranging from 2.34–2.38 Å. There are four inequivalent Si+1.71- sites. In the first Si+1.71- site, Si+1.71- is bonded in a 6-coordinate geometry to one Nb2+, four equivalent Ni1+, and one Si+1.71- atom. The Si–Si bond length is 2.35 Å. In the second Si+1.71- site, Si+1.71- is bonded in a 10-coordinate geometry to eight Nb2+ and two equivalent Si+1.71- atoms. There are one shorter (2.51 Å) and one longer (2.52 Å) Si–Si bond lengths. In the third Si+1.71- site, Si+1.71- is bonded in a 9-coordinate geometry to five Nb2+ and four equivalent Ni1+ atoms. In the fourth Si+1.71- site, Si+1.71- is bonded in a 12-coordinate geometry to four Nb2+ and four equivalent Ni1+ atoms.« less

Authors:

The Materials Project

Publication Date:

Thu Jul 23 00:00:00 EDT 2020

Other Number(s):

mp-1193423

DOE Contract Number:  

AC02-05CH11231; EDCBEE

Research Org.:

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). LBNL Materials Project

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

Collaborations:

MIT; UC Berkeley; Duke; U Louvain

Subject:

36 MATERIALS SCIENCE

Keywords:

crystal structure; Nb4Si7Ni4; Nb-Ni-Si

OSTI Identifier:

1653778

DOI:

https://doi.org/10.17188/1653778