Materials Data on Nb8PtSe20 by Materials Project
Nb8PtSe20 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of one Nb8PtSe20 sheet oriented in the (2, 0, 1) direction. there are four inequivalent Nb+4.75+ sites. In the first Nb+4.75+ site, Nb+4.75+ is bonded to six Se2- atoms to form distorted edge-sharing NbSe6 pentagonal pyramids. There are a spread of Nb–Se bond distances ranging from 2.61–2.64 Å. In the second Nb+4.75+ site, Nb+4.75+ is bonded to six Se2- atoms to form distorted NbSe6 pentagonal pyramids that share edges with two equivalent NbSe7 pentagonal bipyramids and edges with four NbSe6 pentagonal pyramids. There are a spread of Nb–Se bond distances ranging from 2.61–2.64 Å. In the third Nb+4.75+ site, Nb+4.75+ is bonded to seven Se2- atoms to form distorted NbSe7 pentagonal bipyramids that share edges with two equivalent NbSe6 pentagonal pyramids and faces with two equivalent NbSe7 pentagonal bipyramids. There are a spread of Nb–Se bond distances ranging from 2.63–2.86 Å. In the fourth Nb+4.75+ site, Nb+4.75+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Nb–Se bond distances ranging from 2.67–2.83 Å. Pt2+ is bonded in a square co-planar geometry to four Se2- atoms. There are two shorter (2.46 Å) and two longer (2.47 Å) Pt–Se bond lengths. There are ten inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent Nb+4.75+ and one Pt2+ atom. In the second Se2- site, Se2- is bonded in a 3-coordinate geometry to three Nb+4.75+ atoms. In the third Se2- site, Se2- is bonded in a 3-coordinate geometry to three Nb+4.75+ atoms. In the fourth Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb+4.75+ atoms. In the fifth Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Nb+4.75+ atoms. In the sixth Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to three Nb+4.75+ atoms. In the seventh Se2- site, Se2- is bonded in a 3-coordinate geometry to two equivalent Nb+4.75+ and one Pt2+ atom. In the eighth Se2- site, Se2- is bonded in a 3-coordinate geometry to three Nb+4.75+ atoms. In the ninth Se2- site, Se2- is bonded in a 4-coordinate geometry to four Nb+4.75+ atoms. In the tenth Se2- site, Se2- is bonded in a 3-coordinate geometry to three Nb+4.75+ atoms.