Materials Data on Fe2Cu3(Sn3Se8)2 by Materials Project
Fe2Cu3(Sn3Se8)2 is beta indium sulfide-derived structured and crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six Se2- atoms to form FeSe6 octahedra that share corners with four CuSe4 tetrahedra and edges with six SnSe6 octahedra. There are a spread of Fe–Se bond distances ranging from 2.41–2.52 Å. In the second Fe3+ site, Fe3+ is bonded to six Se2- atoms to form FeSe6 octahedra that share corners with five CuSe4 tetrahedra and edges with six SnSe6 octahedra. There are a spread of Fe–Se bond distances ranging from 2.40–2.48 Å. There are three inequivalent Cu+1.33+ sites. In the first Cu+1.33+ site, Cu+1.33+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with three FeSe6 octahedra and corners with nine SnSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–64°. There are a spread of Cu–Se bond distances ranging from 2.41–2.50 Å. In the second Cu+1.33+ site, Cu+1.33+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with three FeSe6 octahedra and corners with nine SnSe6 octahedra. The corner-sharing octahedra tilt angles range from 48–64°. There are a spread of Cu–Se bond distances ranging from 2.41–2.51 Å. In the third Cu+1.33+ site, Cu+1.33+ is bonded to four Se2- atoms to form CuSe4 tetrahedra that share corners with three FeSe6 octahedra and corners with nine SnSe6 octahedra. The corner-sharing octahedra tilt angles range from 47–61°. There are a spread of Cu–Se bond distances ranging from 2.40–2.49 Å. There are four inequivalent Sn+3.67+ sites. In the first Sn+3.67+ site, Sn+3.67+ is bonded to six Se2- atoms to form SnSe6 octahedra that share corners with five CuSe4 tetrahedra, edges with two equivalent FeSe6 octahedra, and edges with four SnSe6 octahedra. There are a spread of Sn–Se bond distances ranging from 2.72–2.78 Å. In the second Sn+3.67+ site, Sn+3.67+ is bonded to six Se2- atoms to form SnSe6 octahedra that share corners with four CuSe4 tetrahedra, edges with two equivalent FeSe6 octahedra, and edges with four SnSe6 octahedra. There are a spread of Sn–Se bond distances ranging from 2.72–2.76 Å. In the third Sn+3.67+ site, Sn+3.67+ is bonded to six Se2- atoms to form SnSe6 octahedra that share corners with four CuSe4 tetrahedra, edges with two FeSe6 octahedra, and edges with four SnSe6 octahedra. There are a spread of Sn–Se bond distances ranging from 2.70–2.78 Å. In the fourth Sn+3.67+ site, Sn+3.67+ is bonded to six Se2- atoms to form SnSe6 octahedra that share corners with five CuSe4 tetrahedra, edges with two FeSe6 octahedra, and edges with four SnSe6 octahedra. There are a spread of Sn–Se bond distances ranging from 2.71–2.75 Å. There are twelve inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to three Sn+3.67+ atoms. In the second Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Cu+1.33+ and three Sn+3.67+ atoms. In the third Se2- site, Se2- is bonded in a 3-coordinate geometry to one Fe3+ and two equivalent Sn+3.67+ atoms. In the fourth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Fe3+, one Cu+1.33+, and two equivalent Sn+3.67+ atoms. In the fifth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Fe3+, one Cu+1.33+, and two Sn+3.67+ atoms. In the sixth Se2- site, Se2- is bonded in a 3-coordinate geometry to one Fe3+ and two Sn+3.67+ atoms. In the seventh Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Cu+1.33+ and three Sn+3.67+ atoms. In the eighth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Cu+1.33+ and three Sn+3.67+ atoms. In the ninth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Fe3+, one Cu+1.33+, and two equivalent Sn+3.67+ atoms. In the tenth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Fe3+, one Cu+1.33+, and two equivalent Sn+3.67+ atoms. In the eleventh Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Fe3+, one Cu+1.33+, and two Sn+3.67+ atoms. In the twelfth Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to one Fe3+, one Cu+1.33+, and two Sn+3.67+ atoms.