Materials Data on AlTl2Cu3Se4 by Materials Project

Abstract

Cu3Tl2AlSe4 crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional. there are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to four equivalent Se2- atoms to form a mixture of edge and corner-sharing CuSe4 tetrahedra. All Cu–Se bond lengths are 2.54 Å. In the second Cu1+ site, Cu1+ is bonded to four equivalent Se2- atoms to form CuSe4 tetrahedra that share corners with four equivalent CuSe4 tetrahedra and edges with four equivalent AlSe4 tetrahedra. All Cu–Se bond lengths are 2.50 Å. Tl1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are four shorter (3.20 Å) and four longer (4.04 Å) Tl–Se bond lengths. Al3+ is bonded to four equivalent Se2- atoms to form AlSe4 tetrahedra that share corners with four equivalent AlSe4 tetrahedra and edges with four equivalent CuSe4 tetrahedra. All Al–Se bond lengths are 2.50 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to two equivalent Cu1+, four equivalent Tl1+, and two equivalent Al3+ atoms. In the second Se2- site, Se2- is bonded in a 8-coordinate geometry to four equivalent Cu1+ and four equivalent Tl1+ atoms.