Materials Data on FeCu6(SnS4)2 by Materials Project
FeCu6(SnS4)2 crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional. Fe3+ is bonded to four equivalent S2- atoms to form FeS4 tetrahedra that share corners with twelve CuS4 tetrahedra and edges with two equivalent SnS4 tetrahedra. All Fe–S bond lengths are 2.41 Å. There are two inequivalent Cu+1.17+ sites. In the first Cu+1.17+ site, Cu+1.17+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two equivalent FeS4 tetrahedra, corners with two equivalent SnS4 tetrahedra, corners with eight CuS4 tetrahedra, and an edgeedge with one SnS4 tetrahedra. There are two shorter (2.28 Å) and two longer (2.50 Å) Cu–S bond lengths. In the second Cu+1.17+ site, Cu+1.17+ is bonded to four S2- atoms to form CuS4 tetrahedra that share corners with two equivalent FeS4 tetrahedra, corners with four SnS4 tetrahedra, and corners with eight equivalent CuS4 tetrahedra. There are two shorter (2.26 Å) and two longer (2.30 Å) Cu–S bond lengths. There are two inequivalent Sn3+ sites. In the first Sn3+ site, Sn3+ is bonded to four equivalent S2- atoms to form SnS4 tetrahedra that share corners with twelve CuS4 tetrahedra. All Sn–S bond lengths are 2.48 Å. In the second Sn3+ site, Sn3+ is bonded to four equivalent S2- atoms to form SnS4 tetrahedra that share corners with four equivalent CuS4 tetrahedra, edges with two equivalent FeS4 tetrahedra, and edges with four equivalent CuS4 tetrahedra. All Sn–S bond lengths are 2.53 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to three Cu+1.17+ and one Sn3+ atom to form corner-sharing SCu3Sn tetrahedra. In the second S2- site, S2- is bonded in a 5-coordinate geometry to one Fe3+, three Cu+1.17+, and one Sn3+ atom.