DOE OSTI2020
La4SbTe7 crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional. there are two inequivalent La+2.75+ sites. In the first La+2.75+ site, La+2.75+ is bonded to seven Te2- atoms to form a mixture of distorted edge, face, and corner-sharing LaTe7 pentagonal bipyramids. There are a spread of La–Te bond distances ranging from 3.31–3.46 Å. In the second La+2.75+ site, La+2.75+ is bonded in a 9-coordinate geometry to nine Te2- atoms. There are a spread of La–Te bond distances ranging from 3.31–3.42 Å. Sb3+ is bonded in a square co-planar geometry to four equivalent Te2- atoms. All Sb–Te bond lengths are 3.20 Å. There are four inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to five La+2.75+ atoms to form a mixture of distorted edge and corner-sharing TeLa5 trigonal bipyramids. In the second Te2- site, Te2- is bonded to five La+2.75+ atoms to form a mixture of distorted edge and corner-sharing TeLa5 trigonal bipyramids. In the third Te2- site, Te2- is bonded in a 8-coordinate geometry to four equivalent La+2.75+ and four equivalent Te2- atoms. All Te–Te bond lengths are 3.20 Å. In the fourth Te2- site, Te2- is bonded in a 8-coordinate geometry to four equivalent La+2.75+ and four equivalent Sb3+ atoms.