DOE OSTI2020
Ba5In4Te4S7 crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to six S2- atoms to form distorted BaS6 pentagonal pyramids that share corners with eight equivalent InTe2S2 tetrahedra and faces with two equivalent BaS6 pentagonal pyramids. There are two shorter (3.25 Å) and four longer (3.33 Å) Ba–S bond lengths. In the second Ba2+ site, Ba2+ is bonded in a 4-coordinate geometry to four Te2- and four S2- atoms. There are a spread of Ba–Te bond distances ranging from 3.76–3.84 Å. There are two shorter (3.15 Å) and two longer (3.16 Å) Ba–S bond lengths. In the third Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to two equivalent Te2- and six S2- atoms. There are one shorter (3.85 Å) and one longer (3.87 Å) Ba–Te bond lengths. There are a spread of Ba–S bond distances ranging from 3.30–3.34 Å. There are two inequivalent In3+ sites. In the first In3+ site, In3+ is bonded to two equivalent Te2- and two S2- atoms to form InTe2S2 tetrahedra that share corners with four equivalent BaS6 pentagonal pyramids and corners with three equivalent InTe2S2 tetrahedra. Both In–Te bond lengths are 2.84 Å. There are one shorter (2.49 Å) and one longer (2.51 Å) In–S bond lengths. In the second In3+ site, In3+ is bonded to two equivalent Te2- and two S2- atoms to form distorted corner-sharing InTe2S2 tetrahedra. Both In–Te bond lengths are 2.83 Å. There are one shorter (2.47 Å) and one longer (2.49 Å) In–S bond lengths. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 2-coordinate geometry to three Ba2+ and two equivalent In3+ atoms. In the second Te2- site, Te2- is bonded in a 5-coordinate geometry to three equivalent Ba2+ and two equivalent In3+ atoms. There are four inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Ba2+ and two equivalent In3+ atoms to form SBa2In2 tetrahedra that share corners with two equivalent SBa2In2 tetrahedra, corners with six equivalent SBa4In trigonal bipyramids, and edges with two equivalent SBa4In trigonal bipyramids. In the second S2- site, S2- is bonded to four Ba2+ and one In3+ atom to form distorted SBa4In trigonal bipyramids that share corners with two equivalent SBa4In square pyramids, corners with three equivalent SBa2In2 tetrahedra, corners with two equivalent SBa4In trigonal bipyramids, an edgeedge with one SBa4In square pyramid, an edgeedge with one SBa2In2 tetrahedra, and edges with three equivalent SBa4In trigonal bipyramids. In the third S2- site, S2- is bonded to four Ba2+ and one In3+ atom to form a mixture of distorted edge and corner-sharing SBa4In square pyramids. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to four Ba2+ and one In3+ atom.