Materials Data on La4AsBrO8 by Materials Project

Abstract

La4AsO8Br crystallizes in the tetragonal P4_2/m space group. The structure is three-dimensional. there are two inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 6-coordinate geometry to six O2- and one Br1- atom. There are a spread of La–O bond distances ranging from 2.37–2.62 Å. The La–Br bond length is 3.47 Å. In the second La3+ site, La3+ is bonded in a 6-coordinate geometry to six O2- and one Br1- atom. There are a spread of La–O bond distances ranging from 2.37–2.67 Å. The La–Br bond length is 3.51 Å. As5+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.72 Å) and two longer (1.74 Å) As–O bond length. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent La3+, one As5+, and one Br1- atom. The O–Br bond length is 3.62 Å. In the second O2- site, O2- is bonded to four La3+ atoms to form a mixture of edge and corner-sharing OLa4 tetrahedra. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two La3+, one As5+, and one Br1- atom. The O–Br bond length is 3.49 Å. In the fourth O2- site, O2- is bonded to four equivalent La3+ atoms to form a mixture of distorted edge and corner-sharing OLa4 tetrahedra. In the fifth O2- site, O2- is bonded to four equivalent La3+ atoms to form a mixture of distorted edge and corner-sharing OLa4 tetrahedra. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent La3+, one As5+, and one Br1- atom. The O–Br bond length is 3.63 Å. In the seventh O2- site, O2- is bonded to four La3+ atoms to form a mixture of edge and corner-sharing OLa4 tetrahedra. Br1- is bonded in a 4-coordinate geometry to four La3+ and four O2- atoms.