DOE OSTI2020
Sr10WMo4Fe5O30 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are five inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, a faceface with one WO6 octahedra, faces with three MoO6 octahedra, and faces with four FeO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.69–3.09 Å. In the second Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, faces with four MoO6 octahedra, and faces with four FeO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.67–3.02 Å. In the third Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, faces with four MoO6 octahedra, and faces with four FeO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.68–3.01 Å. In the fourth Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, a faceface with one WO6 octahedra, faces with three MoO6 octahedra, and faces with four FeO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.64–3.06 Å. In the fifth Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with twelve SrO12 cuboctahedra, faces with six SrO12 cuboctahedra, faces with two equivalent WO6 octahedra, faces with two equivalent MoO6 octahedra, and faces with four FeO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.67–3.06 Å. W2+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six FeO6 octahedra and faces with eight SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 1–14°. There is two shorter (1.93 Å) and four longer (1.96 Å) W–O bond length. There are two inequivalent Mo6+ sites. In the first Mo6+ site, Mo6+ is bonded to six O2- atoms to form MoO6 octahedra that share corners with six FeO6 octahedra and faces with eight SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 1–14°. There are a spread of Mo–O bond distances ranging from 1.89–2.06 Å. In the second Mo6+ site, Mo6+ is bonded to six O2- atoms to form MoO6 octahedra that share corners with six FeO6 octahedra and faces with eight SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 1–13°. There are a spread of Mo–O bond distances ranging from 1.93–2.04 Å. There are three inequivalent Fe+2.80+ sites. In the first Fe+2.80+ site, Fe+2.80+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent WO6 octahedra, corners with four equivalent MoO6 octahedra, and faces with eight SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 1–13°. There are a spread of Fe–O bond distances ranging from 2.05–2.13 Å. In the second Fe+2.80+ site, Fe+2.80+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent WO6 octahedra, corners with four MoO6 octahedra, and faces with eight SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 1–14°. There are a spread of Fe–O bond distances ranging from 1.99–2.11 Å. In the third Fe+2.80+ site, Fe+2.80+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six MoO6 octahedra and faces with eight SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 1–13°. There are a spread of Fe–O bond distances ranging from 2.00–2.05 Å. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded to four Sr2+, one Mo6+, and one Fe+2.80+ atom to form a mixture of distorted corner and edge-sharing OSr4FeMo octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the second O2- site, O2- is bonded to four Sr2+, one Mo6+, and one Fe+2.80+ atom to form a mixture of distorted corner and edge-sharing OSr4FeMo octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the third O2- site, O2- is bonded to four Sr2+, one Mo6+, and one Fe+2.80+ atom to form a mixture of distorted corner and edge-sharing OSr4FeMo octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the fourth O2- site, O2- is bonded to four Sr2+, one Mo6+, and one Fe+2.80+ atom to form a mixture of distorted corner and edge-sharing OSr4FeMo octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the fifth O2- site, O2- is bonded in a distorted linear geometry to four Sr2+, one W2+, and one Fe+2.80+ atom. In the sixth O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+, one Mo6+, and one Fe+2.80+ atom. In the seventh O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+, one Mo6+, and one Fe+2.80+ atom. In the eighth O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+, one Mo6+, and one Fe+2.80+ atom. In the ninth O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+, one Mo6+, and one Fe+2.80+ atom. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+, one W2+, and one Fe+2.80+ atom. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+, one W2+, and one Fe+2.80+ atom. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+, one Mo6+, and one Fe+2.80+ atom. In the thirteenth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+, one Mo6+, and one Fe+2.80+ atom. In the fourteenth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+, one Mo6+, and one Fe+2.80+ atom. In the fifteenth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+, one Mo6+, and one Fe+2.80+ atom.