Materials Data on LaNb2CuBrO7 by Materials Project

Abstract

LaNb2CuO7Br crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. La3+ is bonded to twelve O2- atoms to form a mixture of corner and face-sharing LaO12 cuboctahedra. There are eight shorter (2.69 Å) and four longer (2.79 Å) La–O bond lengths. Nb5+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Nb–O bond distances ranging from 1.80–2.26 Å. Cu2+ is bonded in a distorted linear geometry to two equivalent O2- and four equivalent Br1- atoms. Both Cu–O bond lengths are 1.84 Å. All Cu–Br bond lengths are 2.79 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent La3+ and two equivalent Nb5+ atoms. In the second O2- site, O2- is bonded in a linear geometry to one Nb5+ and one Cu2+ atom. In the third O2- site, O2- is bonded to four equivalent La3+ and two equivalent Nb5+ atoms to form a mixture of distorted edge and corner-sharing OLa4Nb2 octahedra. The corner-sharing octahedral tilt angles are 0°. Br1- is bonded in a square co-planar geometry to four equivalent Cu2+ atoms.