DOI: 10.17188/1722720
title: Materials Data on Nb5Cr3Se20 by Materials Project

description: Nb3CrSe10(NbCrSe5)2 crystallizes in the monoclinic Pm space group. The structure is two-dimensional and consists of one Nb3CrSe10 sheet oriented in the (0, 0, 1) direction and one NbCrSe5 sheet oriented in the (0, 0, 1) direction. In the Nb3CrSe10 sheet, there are three inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Nb–Se bond distances ranging from 2.67–2.80 Å. In the second Nb5+ site, Nb5+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Nb–Se bond distances ranging from 2.67–2.78 Å. In the third Nb5+ site, Nb5+ is bonded to six Se2- atoms to form distorted NbSe6 octahedra that share edges with two equivalent NbSe6 octahedra and edges with two equivalent CrSe6 octahedra. There are a spread of Nb–Se bond distances ranging from 2.49–2.82 Å. Cr5+ is bonded to six Se2- atoms to form CrSe6 octahedra that share edges with two equivalent NbSe6 octahedra and edges with two equivalent CrSe6 octahedra. There are a spread of Cr–Se bond distances ranging from 2.52–2.58 Å. There are ten inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ atoms. In the second Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ atoms. In the third Se2- site, Se2- is bonded to four Nb5+ atoms to form distorted corner-sharing SeNb4 tetrahedra. In the fourth Se2- site, Se2- is bonded in a 4-coordinate geometry to three Nb5+ and one Cr5+ atom. In the fifth Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ atoms. In the sixth Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ atoms. In the seventh Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to three Nb5+ atoms. In the eighth Se2- site, Se2- is bonded in a 3-coordinate geometry to one Nb5+ and two equivalent Cr5+ atoms. In the ninth Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent Nb5+ and one Cr5+ atom. In the tenth Se2- site, Se2- is bonded in a 3-coordinate geometry to one Nb5+ and two equivalent Cr5+ atoms. In the NbCrSe5 sheet, Nb5+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Nb–Se bond distances ranging from 2.67–2.77 Å. Cr5+ is bonded to six Se2- atoms to form edge-sharing CrSe6 octahedra. There are a spread of Cr–Se bond distances ranging from 2.48–2.55 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ atoms. In the second Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ atoms. Both Se–Nb bond lengths are 2.69 Å. In the third Se2- site, Se2- is bonded in a 4-coordinate geometry to three equivalent Nb5+ and one Cr5+ atom. In the fourth Se2- site, Se2- is bonded in a 4-coordinate geometry to three equivalent Nb5+ and one Cr5+ atom. The Se–Cr bond length is 2.55 Å. In the fifth Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ atoms. In the sixth Se2- site, Se2- is bonded in a 3-coordinate geometry to one Nb5+ and two equivalent Cr5+ atoms. In the seventh Se2- site, Se2- is bonded in a 3-coordinate geometry to one Nb5+ and two equivalent Cr5+ atoms. The Se–Nb bond length is 2.75 Å. Both Se–Cr bond lengths are 2.54 Å. In the eighth Se2- site, Se2- is bonded in a 3-coordinate geometry to three equivalent Cr5+ atoms.