DOE OSTI2020
TiO crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are twelve inequivalent Ti2+ sites. In the first Ti2+ site, Ti2+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with four TiO6 octahedra, corners with two equivalent TiO5 square pyramids, an edgeedge with one TiO6 octahedra, and edges with nine TiO5 square pyramids. The corner-sharing octahedra tilt angles range from 9–17°. There are a spread of Ti–O bond distances ranging from 2.06–2.17 Å. In the second Ti2+ site, Ti2+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with four equivalent TiO5 square pyramids, edges with ten TiO6 octahedra, and edges with two equivalent TiO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.11 Å) and four longer (2.14 Å) Ti–O bond lengths. In the third Ti2+ site, Ti2+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with four equivalent TiO5 square pyramids, edges with ten TiO6 octahedra, and edges with two equivalent TiO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.13 Å) and four longer (2.14 Å) Ti–O bond lengths. In the fourth Ti2+ site, Ti2+ is bonded to five O2- atoms to form TiO5 square pyramids that share corners with two equivalent TiO6 octahedra, corners with five TiO5 square pyramids, edges with seven TiO6 octahedra, and an edgeedge with one TiO5 square pyramid. The corner-sharing octahedra tilt angles range from 17–19°. There are a spread of Ti–O bond distances ranging from 2.10–2.17 Å. In the fifth Ti2+ site, Ti2+ is bonded to five O2- atoms to form TiO5 square pyramids that share corners with two equivalent TiO6 octahedra, corners with five TiO5 square pyramids, edges with seven TiO6 octahedra, and an edgeedge with one TiO5 square pyramid. The corner-sharing octahedra tilt angles range from 16–19°. There are a spread of Ti–O bond distances ranging from 2.09–2.18 Å. In the sixth Ti2+ site, Ti2+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra, edges with seven TiO6 octahedra, and edges with four TiO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–17°. There are a spread of Ti–O bond distances ranging from 2.08–2.23 Å. In the seventh Ti2+ site, Ti2+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with four equivalent TiO6 octahedra, edges with eight TiO6 octahedra, and edges with four TiO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Ti–O bond distances ranging from 2.10–2.18 Å. In the eighth Ti2+ site, Ti2+ is bonded in a square co-planar geometry to four O2- atoms. There are two shorter (2.02 Å) and two longer (2.10 Å) Ti–O bond lengths. In the ninth Ti2+ site, Ti2+ is bonded to five O2- atoms to form TiO5 square pyramids that share corners with five TiO5 square pyramids, edges with two equivalent TiO6 octahedra, and edges with five TiO5 square pyramids. There are a spread of Ti–O bond distances ranging from 2.06–2.15 Å. In the tenth Ti2+ site, Ti2+ is bonded to five O2- atoms to form TiO5 square pyramids that share corners with five TiO5 square pyramids, edges with two equivalent TiO6 octahedra, and edges with five TiO5 square pyramids. There are a spread of Ti–O bond distances ranging from 2.13–2.18 Å. In the eleventh Ti2+ site, Ti2+ is bonded to five O2- atoms to form TiO5 square pyramids that share corners with two equivalent TiO6 octahedra, corners with five TiO5 square pyramids, and edges with five TiO5 square pyramids. The corner-sharing octahedral tilt angles are 9°. There are a spread of Ti–O bond distances ranging from 2.05–2.16 Å. In the twelfth Ti2+ site, Ti2+ is bonded to five O2- atoms to form TiO5 square pyramids that share corners with five TiO5 square pyramids, an edgeedge with one TiO6 octahedra, and edges with five TiO5 square pyramids. There are a spread of Ti–O bond distances ranging from 2.01–2.14 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded to six Ti2+ atoms to form OTi6 octahedra that share corners with six OTi6 octahedra, edges with seven OTi6 octahedra, and edges with four OTi5 square pyramids. The corner-sharing octahedra tilt angles range from 0–17°. In the second O2- site, O2- is bonded to six Ti2+ atoms to form OTi6 octahedra that share corners with four equivalent OTi6 octahedra, edges with eight OTi6 octahedra, and edges with four OTi5 square pyramids. The corner-sharing octahedra tilt angles range from 0–3°. In the third O2- site, O2- is bonded to six Ti2+ atoms to form OTi6 octahedra that share corners with four OTi6 octahedra, corners with two equivalent OTi5 square pyramids, an edgeedge with one OTi6 octahedra, and edges with nine OTi5 square pyramids. The corner-sharing octahedra tilt angles range from 9–17°. In the fourth O2- site, O2- is bonded to five Ti2+ atoms to form OTi5 square pyramids that share corners with two equivalent OTi6 octahedra, corners with five OTi5 square pyramids, edges with seven OTi6 octahedra, and an edgeedge with one OTi5 square pyramid. The corner-sharing octahedral tilt angles are 16°. In the fifth O2- site, O2- is bonded to five Ti2+ atoms to form OTi5 square pyramids that share corners with two equivalent OTi6 octahedra, corners with five OTi5 square pyramids, edges with seven OTi6 octahedra, and an edgeedge with one OTi5 square pyramid. The corner-sharing octahedra tilt angles range from 15–16°. In the sixth O2- site, O2- is bonded to six Ti2+ atoms to form OTi6 octahedra that share corners with two equivalent OTi6 octahedra, corners with four equivalent OTi5 square pyramids, edges with ten OTi6 octahedra, and edges with two equivalent OTi5 square pyramids. The corner-sharing octahedral tilt angles are 0°. In the seventh O2- site, O2- is bonded to six Ti2+ atoms to form OTi6 octahedra that share corners with two equivalent OTi6 octahedra, corners with four equivalent OTi5 square pyramids, edges with ten OTi6 octahedra, and edges with two equivalent OTi5 square pyramids. The corner-sharing octahedral tilt angles are 0°. In the eighth O2- site, O2- is bonded to five Ti2+ atoms to form OTi5 square pyramids that share corners with two equivalent OTi6 octahedra, corners with five OTi5 square pyramids, and edges with five OTi5 square pyramids. The corner-sharing octahedra tilt angles range from 9–13°. In the ninth O2- site, O2- is bonded to five Ti2+ atoms to form OTi5 square pyramids that share corners with five OTi5 square pyramids, an edgeedge with one OTi6 octahedra, and edges with five OTi5 square pyramids. In the tenth O2- site, O2- is bonded to five Ti2+ atoms to form OTi5 square pyramids that share corners with five OTi5 square pyramids, edges with two equivalent OTi6 octahedra, and edges with five OTi5 square pyramids. In the eleventh O2- site, O2- is bonded to five Ti2+ atoms to form OTi5 square pyramids that share corners with five OTi5 square pyramids, edges with two equivalent OTi6 octahedra, and edges with five OTi5 square pyramids. In the twelfth O2- site, O2- is bonded in a square co-planar geometry to four Ti2+ atoms.