Materials Data on La2Cr2O5 by Materials Project

Abstract

La2Cr2O5 crystallizes in the orthorhombic Ima2 space group. The structure is three-dimensional. La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.30–2.96 Å. There are two inequivalent Cr2+ sites. In the first Cr2+ site, Cr2+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent CrO6 octahedra and corners with two equivalent CrO4 trigonal pyramids. The corner-sharing octahedral tilt angles are 20°. There are four shorter (2.03 Å) and two longer (2.04 Å) Cr–O bond lengths. In the second Cr2+ site, Cr2+ is bonded to four O2- atoms to form CrO4 trigonal pyramids that share corners with two equivalent CrO6 octahedra and corners with two equivalent CrO4 trigonal pyramids. The corner-sharing octahedral tilt angles are 28°. There are a spread of Cr–O bond distances ranging from 2.05–2.31 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to four equivalent La3+ and two equivalent Cr2+ atoms. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three equivalent La3+ and two Cr2+ atoms. In the third O2- site, O2- is bonded to two equivalent La3+ and two equivalent Cr2+ atoms to form corner-sharing OLa2Cr2 tetrahedra.