Materials Data on Mn4Nb2Si5 by Materials Project

Abstract

Nb2Mn4Si5 crystallizes in the orthorhombic Ibam space group. The structure is three-dimensional. Nb2+ is bonded to six Si+2.40- atoms to form distorted NbSi6 octahedra that share corners with four equivalent NbSi6 octahedra, corners with six equivalent MnSi7 pentagonal bipyramids, edges with two equivalent NbSi6 octahedra, faces with two equivalent NbSi6 octahedra, and faces with four equivalent MnSi7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There are a spread of Nb–Si bond distances ranging from 2.60–2.62 Å. There are two inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to seven Si+2.40- atoms to form distorted MnSi7 pentagonal bipyramids that share corners with six equivalent NbSi6 octahedra, corners with six equivalent MnSi7 pentagonal bipyramids, edges with three equivalent MnSi7 pentagonal bipyramids, faces with four equivalent NbSi6 octahedra, and faces with two equivalent MnSi7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 41–55°. There are a spread of Mn–Si bond distances ranging from 2.46–2.90 Å. In the second Mn2+ site, Mn2+ is bonded in a 7-coordinate geometry to seven Si+2.40- atoms. There are a spread of Mn–Si bond distances ranging from 2.31–2.81 Å. There are three inequivalent Si+2.40- sites. In the first Si+2.40- site, Si+2.40- is bonded in a 8-coordinate geometry to two equivalent Nb2+, five Mn2+, and one Si+2.40- atom. The Si–Si bond length is 2.42 Å. In the second Si+2.40- site, Si+2.40- is bonded in a 9-coordinate geometry to four equivalent Nb2+ and five Mn2+ atoms. In the third Si+2.40- site, Si+2.40- is bonded in a 10-coordinate geometry to eight Mn2+ and two equivalent Si+2.40- atoms. Both Si–Si bond lengths are 2.58 Å.