Materials Data on Nb2Zn4O9 by Materials Project

Abstract

Zn4Nb2O9 is Ilmenite-like structured and crystallizes in the trigonal P-3c1 space group. The structure is three-dimensional. Nb5+ is bonded to six O2- atoms to form distorted NbO6 pentagonal pyramids that share corners with six equivalent ZnO6 octahedra and a faceface with one NbO6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 48–57°. There are three shorter (1.91 Å) and three longer (2.19 Å) Nb–O bond lengths. There are two inequivalent Zn2+ sites. In the first Zn2+ site, Zn2+ is bonded to six equivalent O2- atoms to form ZnO6 octahedra that share corners with six equivalent NbO6 pentagonal pyramids and edges with three equivalent ZnO6 octahedra. There are three shorter (2.09 Å) and three longer (2.20 Å) Zn–O bond lengths. In the second Zn2+ site, Zn2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are three shorter (2.00 Å) and three longer (2.43 Å) Zn–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Nb5+ and two equivalent Zn2+ atoms to form a mixture of distorted corner and edge-sharing ONb2Zn2 trigonal pyramids. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Nb5+ and three Zn2+ atoms.