Hf9Re4O3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Re(1) and two equivalent O(1) atoms. In the second Hf site, Hf(2) is bonded in a 2-coordinate geometry to one Re(2), three equivalent Re(1), and two equivalent O(1) atoms. There are two inequivalent Re sites. In the first Re site, Re(1) is bonded to two equivalent Hf(1), six equivalent Hf(2), two equivalent Re(1), and two equivalent Re(2) atoms to form distorted ReHf8Re4 cuboctahedra that share corners with four equivalent Re(1)Hf8Re4 cuboctahedra, corners with four equivalent O(1)Hf6 octahedra, faces with two equivalent Re(2)Hf6Re6 cuboctahedra, faces with six equivalent Re(1)Hf8Re4 cuboctahedra, and faces with four equivalent O(1)Hf6 octahedra. The corner-sharing octahedral tilt angles are 40°. In the second Re site, Re(2) is bonded to six equivalent Hf(2) and six equivalent Re(1) atoms to form ReHf6Re6 cuboctahedra that share edges with six equivalent O(1)Hf6 octahedra, faces with two equivalent Re(2)Hf6Re6 cuboctahedra, and faces with six equivalent Re(1)Hf8Re4 cuboctahedra. O(1) is bonded to two equivalent Hf(1) and four equivalent Hf(2) atoms to form OHf6 octahedra that share corners with four equivalent Re(1)Hf8Re4 cuboctahedra, corners with six equivalent O(1)Hf6 octahedra, edges with two equivalent Re(2)Hf6Re6 cuboctahedra, and faces with four equivalent Re(1)Hf8Re4 cuboctahedra. The corner-sharing octahedral tilt angles range from 36-45°.
Hf9Re4O3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Re(1) and two equivalent O(1) atoms. Both Hf(1)-Re(1) bond lengths are 2.82 Å. Both Hf(1)-O(1) bond lengths are 2.23 Å. In the second Hf site, Hf(2) is bonded in a 2-coordinate geometry to one Re(2), three equivalent Re(1), and two equivalent O(1) atoms. The Hf(2)-Re(2) bond length is 2.99 Å. There is one shorter (2.96 Å) and two longer (3.01 Å) Hf(2)-Re(1) bond lengths. Both Hf(2)-O(1) bond lengths are 2.28 Å. There are two inequivalent Re sites. In the first Re site, Re(1) is bonded to two equivalent Hf(1), six equivalent Hf(2), two equivalent Re(1), and two equivalent Re(2) atoms to form distorted ReHf8Re4 cuboctahedra that share corners with four equivalent Re(1)Hf8Re4 cuboctahedra, corners with four equivalent O(1)Hf6 octahedra, faces with two equivalent Re(2)Hf6Re6 cuboctahedra, faces with six equivalent Re(1)Hf8Re4 cuboctahedra, and faces with four equivalent O(1)Hf6 octahedra. The corner-sharing octahedral tilt angles are 40°. Both Re(1)-Re(1) bond lengths are 2.78 Å. Both Re(1)-Re(2) bond lengths are 2.66 Å. In the second Re site, Re(2) is bonded to six equivalent Hf(2) and six equivalent Re(1) atoms to form ReHf6Re6 cuboctahedra that share edges with six equivalent O(1)Hf6 octahedra, faces with two equivalent Re(2)Hf6Re6 cuboctahedra, and faces with six equivalent Re(1)Hf8Re4 cuboctahedra. O(1) is bonded to two equivalent Hf(1) and four equivalent Hf(2) atoms to form OHf6 octahedra that share corners with four equivalent Re(1)Hf8Re4 cuboctahedra, corners with six equivalent O(1)Hf6 octahedra, edges with two equivalent Re(2)Hf6Re6 cuboctahedra, and faces with four equivalent Re(1)Hf8Re4 cuboctahedra. The corner-sharing octahedral tilt angles range from 36-45°.