Materials Data on La4Si2Se3O7 by Materials Project

Abstract

La4Si2Se3O7 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. there are two inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 9-coordinate geometry to three Se2- and six O2- atoms. There are one shorter (3.01 Å) and two longer (3.06 Å) La–Se bond lengths. There are a spread of La–O bond distances ranging from 2.58–2.71 Å. In the second La3+ site, La3+ is bonded in a 6-coordinate geometry to three Se2- and three O2- atoms. There are one shorter (3.03 Å) and two longer (3.05 Å) La–Se bond lengths. There are one shorter (2.44 Å) and two longer (2.56 Å) La–O bond lengths. Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.65–1.67 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to four La3+ atoms. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to four equivalent La3+ and two equivalent O2- atoms. Both Se–O bond lengths are 3.49 Å. In the third Se2- site, Se2- is bonded in a distorted square co-planar geometry to four equivalent La3+ atoms. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three La3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Si4+ and one Se2- atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three La3+ and one Si4+ atom.