Materials Data on Cs2NbAgSe4 by Materials Project
Cs2NbAgSe4 crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. Cs1+ is bonded to eight equivalent Se2- atoms to form distorted CsSe8 hexagonal bipyramids that share corners with four equivalent CsSe8 hexagonal bipyramids, corners with two equivalent NbSe4 tetrahedra, corners with four equivalent AgSe4 tetrahedra, edges with six equivalent CsSe8 hexagonal bipyramids, edges with two equivalent AgSe4 tetrahedra, edges with three equivalent NbSe4 tetrahedra, and faces with two equivalent CsSe8 hexagonal bipyramids. There are a spread of Cs–Se bond distances ranging from 3.72–4.02 Å. Nb5+ is bonded to four equivalent Se2- atoms to form NbSe4 tetrahedra that share corners with four equivalent CsSe8 hexagonal bipyramids, edges with six equivalent CsSe8 hexagonal bipyramids, and edges with two equivalent AgSe4 tetrahedra. All Nb–Se bond lengths are 2.44 Å. Ag1+ is bonded to four equivalent Se2- atoms to form AgSe4 tetrahedra that share corners with eight equivalent CsSe8 hexagonal bipyramids, edges with four equivalent CsSe8 hexagonal bipyramids, and edges with two equivalent NbSe4 tetrahedra. All Ag–Se bond lengths are 2.67 Å. Se2- is bonded in a 1-coordinate geometry to four equivalent Cs1+, one Nb5+, and one Ag1+ atom.