Materials Data on Nd4Cu2O7 by Materials Project

Abstract

Nd4Cu2O7 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Nd–O bond distances ranging from 2.34–2.81 Å. In the second Nd3+ site, Nd3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Nd–O bond distances ranging from 2.32–2.68 Å. There are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded in a square co-planar geometry to four O2- atoms. There are two shorter (1.90 Å) and two longer (2.44 Å) Cu–O bond lengths. In the second Cu1+ site, Cu1+ is bonded in a linear geometry to two equivalent O2- atoms. Both Cu–O bond lengths are 1.83 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four Nd3+ and two Cu1+ atoms to form distorted ONd4Cu2 octahedra that share corners with two equivalent ONd4Cu2 octahedra, corners with twelve ONd4 tetrahedra, edges with two equivalent ONd4Cu2 octahedra, and edges with two ONd4 tetrahedra. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded to four Nd3+ atoms to form ONd4 tetrahedra that share corners with six equivalent ONd4Cu2 octahedra, corners with four ONd4 tetrahedra, an edgeedge with one ONd4Cu2 octahedra, and edges with four ONd4 tetrahedra. The corner-sharing octahedra tilt angles range from 12–85°. In the third O2- site, O2- is bonded in a distorted linear geometry to four Nd3+ and two equivalent Cu1+ atoms. In the fourth O2- site, O2- is bonded to four Nd3+ atoms to form ONd4 tetrahedra that share corners with six equivalent ONd4Cu2 octahedra, corners with four ONd4 tetrahedra, an edgeedge with one ONd4Cu2 octahedra, and edges with four ONd4 tetrahedra. The corner-sharing octahedra tilt angles range from 14–64°.