Materials Data on Cu5Sn2Te7 by Materials Project
Cu5Sn2Te7 is Enargite-like structured and crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are three inequivalent Cu+1.20+ sites. In the first Cu+1.20+ site, Cu+1.20+ is bonded to four Te2- atoms to form CuTe4 tetrahedra that share corners with four equivalent SnTe4 tetrahedra and corners with eight CuTe4 tetrahedra. All Cu–Te bond lengths are 2.59 Å. In the second Cu+1.20+ site, Cu+1.20+ is bonded to four Te2- atoms to form CuTe4 tetrahedra that share corners with five equivalent SnTe4 tetrahedra and corners with seven CuTe4 tetrahedra. There are two shorter (2.58 Å) and two longer (2.59 Å) Cu–Te bond lengths. In the third Cu+1.20+ site, Cu+1.20+ is bonded to four Te2- atoms to form CuTe4 tetrahedra that share corners with four equivalent SnTe4 tetrahedra and corners with eight CuTe4 tetrahedra. There are two shorter (2.58 Å) and two longer (2.59 Å) Cu–Te bond lengths. Sn4+ is bonded to four Te2- atoms to form SnTe4 tetrahedra that share a cornercorner with one SnTe4 tetrahedra and corners with eleven CuTe4 tetrahedra. There are three shorter (2.83 Å) and one longer (2.90 Å) Sn–Te bond lengths. There are four inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to two equivalent Cu+1.20+ and two equivalent Sn4+ atoms to form corner-sharing TeCu2Sn2 tetrahedra. In the second Te2- site, Te2- is bonded to three Cu+1.20+ and one Sn4+ atom to form corner-sharing TeCu3Sn tetrahedra. In the third Te2- site, Te2- is bonded to three Cu+1.20+ and one Sn4+ atom to form corner-sharing TeCu3Sn tetrahedra. In the fourth Te2- site, Te2- is bonded to three Cu+1.20+ and one Sn4+ atom to form corner-sharing TeCu3Sn tetrahedra.