Materials Data on TaV(Cu3Se4)2 by Materials Project
TaV(Cu3Se4)2 is Stannite-like structured and crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional. Ta5+ is bonded to four equivalent Se2- atoms to form TaSe4 tetrahedra that share edges with six CuSe4 tetrahedra. All Ta–Se bond lengths are 2.46 Å. V5+ is bonded to four equivalent Se2- atoms to form VSe4 tetrahedra that share edges with six CuSe4 tetrahedra. All V–Se bond lengths are 2.37 Å. There are three inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with eight CuSe4 tetrahedra, an edgeedge with one TaSe4 tetrahedra, and an edgeedge with one VSe4 tetrahedra. There are two shorter (2.41 Å) and two longer (2.47 Å) Cu–Se bond lengths. In the second Cu1+ site, Cu1+ is bonded to four equivalent Se2- atoms to form CuSe4 tetrahedra that share corners with eight equivalent CuSe4 tetrahedra and edges with two equivalent TaSe4 tetrahedra. All Cu–Se bond lengths are 2.46 Å. In the third Cu1+ site, Cu1+ is bonded to four equivalent Se2- atoms to form CuSe4 tetrahedra that share corners with eight equivalent CuSe4 tetrahedra and edges with two equivalent VSe4 tetrahedra. All Cu–Se bond lengths are 2.42 Å. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to one V5+ and three Cu1+ atoms to form a mixture of distorted edge and corner-sharing SeVCu3 tetrahedra. In the second Se2- site, Se2- is bonded to one Ta5+ and three Cu1+ atoms to form distorted SeTaCu3 tetrahedra that share corners with six SeVCu3 tetrahedra and edges with three equivalent SeTaCu3 tetrahedra.