DOI: 10.17188/1685982
title: Materials Data on Ta4(CuNi3)3 by Materials Project

description: Ta4(Ni3Cu)3 is beta Cu3Ti-derived structured and crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. there are three inequivalent Ta sites. In the first Ta site, Ta is bonded to nine Ni and three Cu atoms to form TaCu3Ni9 cuboctahedra that share corners with two equivalent TaCu3Ni9 cuboctahedra, corners with four equivalent CuTa4Ni8 cuboctahedra, corners with twelve NiTa4Ni8 cuboctahedra, edges with six TaCu3Ni9 cuboctahedra, edges with twelve NiTa4Cu2Ni6 cuboctahedra, faces with five CuTa4Ni8 cuboctahedra, faces with six TaCu3Ni9 cuboctahedra, and faces with nine NiTa4Ni8 cuboctahedra. There are a spread of Ta–Ni bond distances ranging from 2.54–2.65 Å. There are one shorter (2.65 Å) and two longer (2.67 Å) Ta–Cu bond lengths. In the second Ta site, Ta is bonded to eight Ni and four Cu atoms to form TaCu4Ni8 cuboctahedra that share corners with two equivalent TaCu2Ni10 cuboctahedra, corners with eight equivalent NiTa4Cu4Ni4 cuboctahedra, corners with eight equivalent CuTa4Ni8 cuboctahedra, edges with six TaCu3Ni9 cuboctahedra, edges with twelve NiTa4Cu2Ni6 cuboctahedra, faces with six TaCu3Ni9 cuboctahedra, faces with six CuTa4Ni8 cuboctahedra, and faces with eight NiTa4Cu4Ni4 cuboctahedra. There are a spread of Ta–Ni bond distances ranging from 2.57–2.63 Å. There are two shorter (2.59 Å) and two longer (2.67 Å) Ta–Cu bond lengths. In the third Ta site, Ta is bonded to ten Ni and two equivalent Cu atoms to form TaCu2Ni10 cuboctahedra that share corners with two equivalent TaCu4Ni8 cuboctahedra, corners with eight equivalent NiTa4Cu2Ni6 cuboctahedra, corners with eight equivalent CuTa4Ni8 cuboctahedra, edges with six TaCu3Ni9 cuboctahedra, edges with twelve NiTa4Cu2Ni6 cuboctahedra, faces with two equivalent CuTa4Ni8 cuboctahedra, faces with six TaCu3Ni9 cuboctahedra, and faces with twelve NiTa4Ni8 cuboctahedra. There are a spread of Ta–Ni bond distances ranging from 2.53–2.64 Å. Both Ta–Cu bond lengths are 2.60 Å. There are five inequivalent Ni sites. In the first Ni site, Ni is bonded to four Ta and eight Ni atoms to form distorted NiTa4Ni8 cuboctahedra that share corners with two equivalent CuTa4Ni8 cuboctahedra, corners with eight equivalent TaCu3Ni9 cuboctahedra, corners with eight equivalent NiTa4Cu2Ni6 cuboctahedra, edges with four equivalent CuTa4Ni8 cuboctahedra, edges with fourteen NiTa4Ni8 cuboctahedra, faces with four equivalent CuTa4Ni8 cuboctahedra, faces with six TaCu3Ni9 cuboctahedra, and faces with ten NiTa4Ni8 cuboctahedra. There are two shorter (2.53 Å) and six longer (2.62 Å) Ni–Ni bond lengths. In the second Ni site, Ni is bonded to four Ta, six Ni, and two equivalent Cu atoms to form distorted NiTa4Cu2Ni6 cuboctahedra that share corners with four equivalent TaCu3Ni9 cuboctahedra, corners with fourteen NiTa4Cu2Ni6 cuboctahedra, edges with six TaCu3Ni9 cuboctahedra, edges with six NiTa4Cu2Ni6 cuboctahedra, edges with six CuTa4Ni8 cuboctahedra, faces with two equivalent CuTa4Ni8 cuboctahedra, faces with four TaCu3Ni9 cuboctahedra, and faces with fourteen NiTa4Ni8 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.54–2.62 Å. Both Ni–Cu bond lengths are 2.62 Å. In the third Ni site, Ni is bonded to four Ta, four Ni, and four Cu atoms to form distorted NiTa4Cu4Ni4 cuboctahedra that share corners with four equivalent TaCu3Ni9 cuboctahedra, corners with four equivalent CuTa4Ni8 cuboctahedra, corners with ten NiTa4Cu2Ni6 cuboctahedra, edges with four equivalent CuTa4Ni8 cuboctahedra, edges with six TaCu3Ni9 cuboctahedra, edges with eight NiTa4Ni8 cuboctahedra, faces with four TaCu3Ni9 cuboctahedra, faces with four CuTa4Ni8 cuboctahedra, and faces with twelve NiTa4Cu2Ni6 cuboctahedra. There are one shorter (2.59 Å) and two longer (2.64 Å) Ni–Ni bond lengths. There are a spread of Ni–Cu bond distances ranging from 2.52–2.66 Å. In the fourth Ni site, Ni is bonded to four Ta, six Ni, and two equivalent Cu atoms to form distorted NiTa4Cu2Ni6 cuboctahedra that share corners with four equivalent TaCu2Ni10 cuboctahedra, corners with four equivalent CuTa4Ni8 cuboctahedra, corners with ten NiTa4Cu2Ni6 cuboctahedra, edges with four CuTa4Ni8 cuboctahedra, edges with six TaCu3Ni9 cuboctahedra, edges with eight NiTa4Ni8 cuboctahedra, faces with two equivalent CuTa4Ni8 cuboctahedra, faces with four TaCu3Ni9 cuboctahedra, and faces with fourteen NiTa4Ni8 cuboctahedra. Both Ni–Ni bond lengths are 2.58 Å. There are one shorter (2.50 Å) and one longer (2.68 Å) Ni–Cu bond lengths. In the fifth Ni site, Ni is bonded to four Ta, four Ni, and four Cu atoms to form distorted NiTa4Cu4Ni4 cuboctahedra that share corners with four equivalent TaCu4Ni8 cuboctahedra, corners with four equivalent CuTa4Ni8 cuboctahedra, corners with ten NiTa4Cu2Ni6 cuboctahedra, edges with four CuTa4Ni8 cuboctahedra, edges with six TaCu3Ni9 cuboctahedra, edges with eight NiTa4Ni8 cuboctahedra, faces with four TaCu3Ni9 cuboctahedra, faces with four CuTa4Ni8 cuboctahedra, and faces with twelve NiTa4Cu2Ni6 cuboctahedra. The Ni–Ni bond length is 2.62 Å. There are a spread of Ni–Cu bond distances ranging from 2.51–2.65 Å. There are two inequivalent Cu sites. In the first Cu site, Cu is bonded to four Ta and eight Ni atoms to form distorted CuTa4Ni8 cuboctahedra that share corners with two equivalent CuTa4Ni8 cuboctahedra, corners with eight TaCu4Ni8 cuboctahedra, corners with eight NiTa4Cu2Ni6 cuboctahedra, edges with four CuTa4Ni8 cuboctahedra, edges with fourteen NiTa4Ni8 cuboctahedra, faces with four CuTa4Ni8 cuboctahedra, faces with six TaCu3Ni9 cuboctahedra, and faces with ten NiTa4Ni8 cuboctahedra. In the second Cu site, Cu is bonded to four Ta and eight Ni atoms to form CuTa4Ni8 cuboctahedra that share corners with eight equivalent TaCu3Ni9 cuboctahedra, corners with ten NiTa4Cu4Ni4 cuboctahedra, edges with six CuTa4Ni8 cuboctahedra, edges with twelve NiTa4Cu2Ni6 cuboctahedra, faces with six TaCu3Ni9 cuboctahedra, faces with six CuTa4Ni8 cuboctahedra, and faces with eight NiTa4Cu4Ni4 cuboctahedra.