DOI: 10.17188/1717169
title: Materials Data on Nb5Si6W5 by Materials Project

description: Nb5W5Si6 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are five inequivalent Nb+2.80+ sites. In the first Nb+2.80+ site, Nb+2.80+ is bonded to six Si4- atoms to form distorted NbSi6 pentagonal pyramids that share corners with seven WSi6 pentagonal pyramids, corners with eight NbSi6 pentagonal pyramids, corners with four equivalent WSi4 tetrahedra, edges with three equivalent NbSi6 pentagonal pyramids, edges with two equivalent WSi4 tetrahedra, faces with three NbSi6 pentagonal pyramids, and faces with four WSi6 pentagonal pyramids. There are a spread of Nb–Si bond distances ranging from 2.59–2.87 Å. In the second Nb+2.80+ site, Nb+2.80+ is bonded to six Si4- atoms to form distorted NbSi6 pentagonal pyramids that share corners with seven WSi6 pentagonal pyramids, corners with eight NbSi6 pentagonal pyramids, corners with four equivalent WSi4 tetrahedra, edges with three equivalent NbSi6 pentagonal pyramids, edges with two equivalent WSi4 tetrahedra, faces with three NbSi6 pentagonal pyramids, and faces with four WSi6 pentagonal pyramids. There are a spread of Nb–Si bond distances ranging from 2.57–2.88 Å. In the third Nb+2.80+ site, Nb+2.80+ is bonded to six Si4- atoms to form distorted NbSi6 pentagonal pyramids that share corners with five WSi6 pentagonal pyramids, corners with ten NbSi6 pentagonal pyramids, corners with four equivalent WSi4 tetrahedra, edges with three equivalent NbSi6 pentagonal pyramids, edges with two equivalent WSi4 tetrahedra, faces with three NbSi6 pentagonal pyramids, and faces with four WSi6 pentagonal pyramids. There are a spread of Nb–Si bond distances ranging from 2.60–2.88 Å. In the fourth Nb+2.80+ site, Nb+2.80+ is bonded to six Si4- atoms to form distorted NbSi6 pentagonal pyramids that share corners with seven NbSi6 pentagonal pyramids, corners with eight WSi6 pentagonal pyramids, corners with four equivalent WSi4 tetrahedra, edges with three equivalent NbSi6 pentagonal pyramids, edges with two equivalent WSi4 tetrahedra, faces with three WSi6 pentagonal pyramids, and faces with four NbSi6 pentagonal pyramids. There are a spread of Nb–Si bond distances ranging from 2.59–2.90 Å. In the fifth Nb+2.80+ site, Nb+2.80+ is bonded to six Si4- atoms to form distorted NbSi6 pentagonal pyramids that share corners with four equivalent WSi6 pentagonal pyramids, corners with eleven NbSi6 pentagonal pyramids, corners with four equivalent WSi4 tetrahedra, edges with three equivalent WSi6 pentagonal pyramids, edges with two equivalent WSi4 tetrahedra, faces with two equivalent WSi6 pentagonal pyramids, and faces with five NbSi6 pentagonal pyramids. There are a spread of Nb–Si bond distances ranging from 2.64–2.92 Å. There are four inequivalent W2+ sites. In the first W2+ site, W2+ is bonded to six Si4- atoms to form distorted WSi6 pentagonal pyramids that share corners with six WSi6 pentagonal pyramids, corners with nine NbSi6 pentagonal pyramids, corners with four equivalent WSi4 tetrahedra, edges with three equivalent NbSi6 pentagonal pyramids, edges with two equivalent WSi4 tetrahedra, faces with two equivalent WSi6 pentagonal pyramids, and faces with five NbSi6 pentagonal pyramids. There are a spread of W–Si bond distances ranging from 2.61–2.90 Å. In the second W2+ site, W2+ is bonded to six Si4- atoms to form distorted WSi6 pentagonal pyramids that share corners with two equivalent WSi6 pentagonal pyramids, corners with thirteen NbSi6 pentagonal pyramids, corners with four equivalent WSi4 tetrahedra, edges with three equivalent WSi6 pentagonal pyramids, edges with two equivalent WSi4 tetrahedra, faces with two equivalent WSi6 pentagonal pyramids, and faces with five NbSi6 pentagonal pyramids. There are a spread of W–Si bond distances ranging from 2.58–2.91 Å. In the third W2+ site, W2+ is bonded to six Si4- atoms to form distorted WSi6 pentagonal pyramids that share corners with six WSi6 pentagonal pyramids, corners with nine NbSi6 pentagonal pyramids, corners with four equivalent WSi4 tetrahedra, edges with three equivalent WSi6 pentagonal pyramids, edges with two equivalent WSi4 tetrahedra, and faces with seven NbSi6 pentagonal pyramids. There are a spread of W–Si bond distances ranging from 2.59–2.93 Å. In the fourth W2+ site, W2+ is bonded to four Si4- atoms to form WSi4 tetrahedra that share corners with six WSi6 pentagonal pyramids, corners with ten NbSi6 pentagonal pyramids, edges with three WSi6 pentagonal pyramids, edges with five NbSi6 pentagonal pyramids, and edges with two equivalent WSi4 tetrahedra. There are one shorter (2.62 Å) and three longer (2.63 Å) W–Si bond lengths. There are five inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 10-coordinate geometry to five Nb+2.80+, three W2+, and two equivalent Si4- atoms. There are one shorter (2.53 Å) and one longer (2.55 Å) Si–Si bond lengths. In the second Si4- site, Si4- is bonded in a 10-coordinate geometry to six Nb+2.80+ and four W2+ atoms. In the third Si4- site, Si4- is bonded in a 10-coordinate geometry to five Nb+2.80+ and five W2+ atoms. In the fourth Si4- site, Si4- is bonded in a 10-coordinate geometry to five Nb+2.80+ and five W2+ atoms. In the fifth Si4- site, Si4- is bonded in a 10-coordinate geometry to four Nb+2.80+ and six W2+ atoms.