Materials Data on Tl2FeCu3Se4 by Materials Project
FeCu3Tl2Se4 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional. Fe3+ is bonded to four equivalent Se2- atoms to form FeSe4 tetrahedra that share corners with four equivalent FeSe4 tetrahedra and edges with four equivalent CuSe4 tetrahedra. All Fe–Se bond lengths are 2.47 Å. 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 2.50 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 FeSe4 tetrahedra. All Cu–Se bond lengths are 2.47 Å. Tl1+ is bonded in a body-centered cubic geometry to eight Se2- atoms. There are four shorter (3.36 Å) and four longer (3.55 Å) Tl–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 8-coordinate geometry to two equivalent Fe3+, two equivalent Cu1+, and four equivalent Tl1+ atoms. In the second Se2- site, Se2- is bonded in a 8-coordinate geometry to four equivalent Cu1+ and four equivalent Tl1+ atoms.