DOI: 10.17188/1318452
title: Materials Data on CaTiO2 by Materials Project

description: CaTiO2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to four O2- atoms to form distorted CaO4 trigonal pyramids that share corners with two equivalent CaO6 octahedra, corners with two equivalent TiO5 trigonal bipyramids, corners with two equivalent CaO4 trigonal pyramids, an edgeedge with one TiO5 trigonal bipyramid, and edges with two equivalent TiO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 85–87°. There are a spread of Ca–O bond distances ranging from 2.26–2.42 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 2.31–2.89 Å. In the third Ca2+ site, Ca2+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of Ca–O bond distances ranging from 2.46–2.55 Å. In the fourth Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 octahedra that share corners with two equivalent TiO5 trigonal bipyramids, a cornercorner with one TiO4 trigonal pyramid, corners with two equivalent CaO4 trigonal pyramids, edges with two equivalent CaO6 octahedra, edges with two equivalent TiO5 trigonal bipyramids, and a faceface with one TiO5 trigonal bipyramid. There are a spread of Ca–O bond distances ranging from 2.25–2.64 Å. There are four inequivalent Ti2+ sites. In the first Ti2+ site, Ti2+ is bonded to four O2- atoms to form TiO4 trigonal pyramids that share a cornercorner with one CaO6 octahedra, corners with two equivalent TiO5 trigonal bipyramids, corners with two equivalent TiO4 trigonal pyramids, an edgeedge with one TiO5 trigonal bipyramid, and edges with two equivalent CaO4 trigonal pyramids. The corner-sharing octahedral tilt angles are 15°. There are a spread of Ti–O bond distances ranging from 1.90–2.02 Å. In the second Ti2+ site, Ti2+ is bonded to five O2- atoms to form TiO5 trigonal bipyramids that share corners with two equivalent TiO5 trigonal bipyramids, corners with two equivalent TiO4 trigonal pyramids, edges with two equivalent CaO6 octahedra, and an edgeedge with one CaO4 trigonal pyramid. There are a spread of Ti–O bond distances ranging from 1.90–2.14 Å. In the third Ti2+ site, Ti2+ is bonded in a T-shaped geometry to three O2- atoms. There are a spread of Ti–O bond distances ranging from 1.94–2.08 Å. In the fourth Ti2+ site, Ti2+ is bonded to five O2- atoms to form distorted TiO5 trigonal bipyramids that share corners with two equivalent CaO6 octahedra, corners with two equivalent TiO5 trigonal bipyramids, corners with two equivalent CaO4 trigonal pyramids, an edgeedge with one TiO4 trigonal pyramid, and a faceface with one CaO6 octahedra. The corner-sharing octahedra tilt angles range from 22–24°. There are a spread of Ti–O bond distances ranging from 1.86–2.22 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ca2+ and two Ti2+ atoms to form OCa2Ti2 trigonal pyramids that share a cornercorner with one OCa3Ti2 trigonal bipyramid and corners with two equivalent OCa2Ti2 trigonal pyramids. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two equivalent Ti2+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Ca2+ and two equivalent Ti2+ atoms. In the fourth O2- site, O2- is bonded to one Ca2+ and three Ti2+ atoms to form OCaTi3 trigonal pyramids that share corners with two equivalent OCaTi3 trigonal pyramids and an edgeedge with one OCa3Ti2 trigonal bipyramid. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to two Ca2+ and two Ti2+ atoms. In the sixth O2- site, O2- is bonded to three Ca2+ and two Ti2+ atoms to form OCa3Ti2 trigonal bipyramids that share corners with two equivalent OCa3Ti2 trigonal bipyramids, a cornercorner with one OCa2Ti2 trigonal pyramid, and an edgeedge with one OCaTi3 trigonal pyramid. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two Ti2+ atoms. In the eighth O2- site, O2- is bonded in a 4-coordinate geometry to four Ca2+ and two Ti2+ atoms.