Materials Data on Nb2CrSe4 by Materials Project
Nb2CrSe4 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Nb+2.50+ sites. In the first Nb+2.50+ site, Nb+2.50+ is bonded in a 7-coordinate geometry to one Cr3+ and six Se2- atoms. The Nb–Cr bond length is 2.43 Å. There are two shorter (2.59 Å) and four longer (2.79 Å) Nb–Se bond lengths. In the second Nb+2.50+ site, Nb+2.50+ is bonded to six equivalent Se2- atoms to form distorted NbSe6 pentagonal pyramids that share faces with two equivalent CrSe6 octahedra. All Nb–Se bond lengths are 2.62 Å. There are two inequivalent Cr3+ sites. In the first Cr3+ site, Cr3+ is bonded to six equivalent Se2- atoms to form CrSe6 octahedra that share faces with two equivalent NbSe6 pentagonal pyramids. All Cr–Se bond lengths are 2.56 Å. In the second Cr3+ site, Cr3+ is bonded in a 9-coordinate geometry to three equivalent Nb+2.50+ and six equivalent Se2- atoms. All Cr–Se bond lengths are 2.64 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-coordinate geometry to three Nb+2.50+ and two Cr3+ atoms. In the second Se2- site, Se2- is bonded in a 3-coordinate geometry to three equivalent Nb+2.50+ atoms.