Materials Data on CaTiO2 by Materials Project
CaTiO2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.55 Å. In the second Ca2+ site, Ca2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.56 Å. In the third Ca2+ site, Ca2+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are two shorter (2.29 Å) and one longer (2.48 Å) Ca–O bond lengths. In the fourth Ca2+ site, Ca2+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are two shorter (2.29 Å) and one longer (2.47 Å) Ca–O bond lengths. There are four inequivalent Ti2+ sites. In the first Ti2+ site, Ti2+ is bonded to five O2- atoms to form TiO5 square pyramids that share corners with two equivalent TiO6 octahedra and edges with four TiO5 square pyramids. The corner-sharing octahedral tilt angles are 49°. 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 TiO5 square pyramids and edges with four TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.95–2.16 Å. In the third Ti2+ site, Ti2+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO5 square pyramids and edges with four TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.95–2.16 Å. 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 and edges with four TiO5 square pyramids. The corner-sharing octahedral tilt angles are 49°. There are a spread of Ti–O bond distances ranging from 2.06–2.17 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to one Ca2+ and three Ti2+ atoms to form distorted OCaTi3 trigonal pyramids that share corners with two equivalent OCa3Ti3 octahedra, a cornercorner with one OCa2Ti3 trigonal bipyramid, corners with two equivalent OCaTi3 trigonal pyramids, edges with three OCa3Ti3 octahedra, and edges with two equivalent OCa2Ti3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 19°. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca2+ and two equivalent Ti2+ atoms. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca2+ and two equivalent Ti2+ atoms. In the fourth O2- site, O2- is bonded to one Ca2+ and three Ti2+ atoms to form distorted OCaTi3 trigonal pyramids that share corners with two equivalent OCa3Ti3 octahedra, a cornercorner with one OCa2Ti3 trigonal bipyramid, corners with two equivalent OCaTi3 trigonal pyramids, edges with three OCa3Ti3 octahedra, and edges with two equivalent OCa2Ti3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 19°. In the fifth O2- site, O2- is bonded to three Ca2+ and three Ti2+ atoms to form OCa3Ti3 octahedra that share corners with two equivalent OCa2Ti3 trigonal bipyramids, corners with two equivalent OCaTi3 trigonal pyramids, edges with four OCa3Ti3 octahedra, an edgeedge with one OCa2Ti3 trigonal bipyramid, and edges with three OCaTi3 trigonal pyramids. In the sixth O2- site, O2- is bonded to two equivalent Ca2+ and three Ti2+ atoms to form distorted OCa2Ti3 trigonal bipyramids that share corners with two equivalent OCa3Ti3 octahedra, a cornercorner with one OCaTi3 trigonal pyramid, an edgeedge with one OCa3Ti3 octahedra, edges with four OCa2Ti3 trigonal bipyramids, and edges with two equivalent OCaTi3 trigonal pyramids. The corner-sharing octahedral tilt angles are 33°. In the seventh O2- site, O2- is bonded to three Ca2+ and three Ti2+ atoms to form OCa3Ti3 octahedra that share corners with two equivalent OCa2Ti3 trigonal bipyramids, corners with two equivalent OCaTi3 trigonal pyramids, edges with four OCa3Ti3 octahedra, an edgeedge with one OCa2Ti3 trigonal bipyramid, and edges with three OCaTi3 trigonal pyramids. In the eighth O2- site, O2- is bonded to two equivalent Ca2+ and three Ti2+ atoms to form distorted OCa2Ti3 trigonal bipyramids that share corners with two equivalent OCa3Ti3 octahedra, a cornercorner with one OCaTi3 trigonal pyramid, an edgeedge with one OCa3Ti3 octahedra, edges with four OCa2Ti3 trigonal bipyramids, and edges with two equivalent OCaTi3 trigonal pyramids. The corner-sharing octahedral tilt angles are 33°.