Materials Data on Hf9Re4O3 by Materials Project

Abstract

Hf9Re4O3 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Hf sites. In the first Hf site, Hf is bonded in a distorted bent 150 degrees geometry to two equivalent Re and two equivalent O atoms. Both Hf–Re bond lengths are 2.83 Å. Both Hf–O bond lengths are 2.25 Å. In the second Hf site, Hf is bonded in a 2-coordinate geometry to four Re and two equivalent O atoms. There are a spread of Hf–Re bond distances ranging from 2.99–3.02 Å. Both Hf–O bond lengths are 2.29 Å. There are two inequivalent Re sites. In the first Re site, Re is bonded to eight Hf and four Re atoms to form distorted ReHf8Re4 cuboctahedra that share corners with four equivalent ReHf8Re4 cuboctahedra, corners with four equivalent OHf6 octahedra, faces with eight ReHf6Re6 cuboctahedra, and faces with four equivalent OHf6 octahedra. The corner-sharing octahedral tilt angles are 40°. There are two shorter (2.68 Å) and two longer (2.80 Å) Re–Re bond lengths. In the second Re site, Re is bonded to six equivalent Hf and six equivalent Re atoms to form ReHf6Re6 cuboctahedra that share edges with six equivalent OHf6 octahedra and faces with eight ReHf6Re6 cuboctahedra. O is bonded to six Hf atoms to form OHf6 octahedra that share corners with four equivalent ReHf8Re4 cuboctahedra, corners with six equivalent OHf6 octahedra, edges with two equivalent ReHf6Re6 cuboctahedra, and faces with four equivalent ReHf8Re4 cuboctahedra. The corner-sharing octahedra tilt angles range from 36–46°.