Materials Data on NbCuO3 by Materials Project
CuNbO3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 7°. There are a spread of Nb–O bond distances ranging from 1.89–2.19 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing NbO6 octahedra. The corner-sharing octahedral tilt angles are 7°. There are a spread of Nb–O bond distances ranging from 1.82–2.26 Å. There are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded in a linear geometry to two equivalent O2- atoms. Both Cu–O bond lengths are 1.88 Å. In the second Cu1+ site, Cu1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.80 Å) and one longer (1.84 Å) Cu–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Nb5+ and one Cu1+ atom. In the second O2- site, O2- is bonded to three Nb5+ and one Cu1+ atom to form distorted edge-sharing ONb3Cu tetrahedra. In the third O2- site, O2- is bonded in a trigonal non-coplanar geometry to two Nb5+ and one Cu1+ atom. In the fourth O2- site, O2- is bonded in a linear geometry to two Nb5+ atoms.