Materials Data on Nb5Cr3Se20 by Materials Project
Nb5Cr3Se20 crystallizes in the monoclinic Pm space group. The structure is two-dimensional and consists of one Nb5Cr3Se20 sheet oriented in the (1, 0, -1) direction. there are five 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 2.67–2.77 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 2.66–2.82 Å. In the third 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 2.66–2.80 Å. In the fourth 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 2.66–2.77 Å. In the fifth 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 2.48–2.82 Å. There are three inequivalent Cr5+ sites. In the first Cr5+ site, Cr5+ is bonded to six Se2- atoms to form edge-sharing CrSe6 octahedra. There are a spread of Cr–Se bond distances ranging from 2.48–2.56 Å. In the second Cr5+ site, Cr5+ is bonded to six Se2- atoms to form edge-sharing CrSe6 octahedra. There are a spread of Cr–Se bond distances ranging from 2.48–2.54 Å. In the third Cr5+ site, 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 five shorter (2.52 Å) and one longer (2.57 Å) Cr–Se bond lengths. There are twenty 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 in a 2-coordinate geometry to two equivalent Nb5+ atoms. In the fourth Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ atoms. In the fifth Se2- site, Se2- is bonded in a 4-coordinate geometry to four Nb5+ atoms. In the sixth Se2- site, Se2- is bonded in a 4-coordinate geometry to three Nb5+ and one Cr5+ atom. In the seventh Se2- site, Se2- is bonded in a 4-coordinate geometry to three Nb5+ and one Cr5+ atom. In the eighth Se2- site, Se2- is bonded in a 4-coordinate geometry to three Nb5+ and one Cr5+ atom. In the ninth Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ atoms. In the tenth Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ atoms. In the eleventh Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ atoms. In the twelfth Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb5+ atoms. In the thirteenth Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to three Nb5+ atoms. In the fourteenth Se2- site, Se2- is bonded in a 3-coordinate geometry to one Nb5+ and two equivalent Cr5+ atoms. In the fifteenth Se2- site, Se2- is bonded in a 3-coordinate geometry to one Nb5+ and two equivalent Cr5+ atoms. In the sixteenth Se2- site, Se2- is bonded in a 3-coordinate geometry to one Nb5+ and two equivalent Cr5+ atoms. In the seventeenth Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent Nb5+ and one Cr5+ atom. In the eighteenth Se2- site, Se2- is bonded in a 3-coordinate geometry to three Cr5+ atoms. In the nineteenth Se2- site, Se2- is bonded in a 3-coordinate geometry to three Cr5+ atoms. In the twentieth Se2- site, Se2- is bonded in a 3-coordinate geometry to one Nb5+ and two equivalent Cr5+ atoms.