CaTiO2 crystallizes in the triclinic P1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(4), one O(6), and two equivalent O(7) atoms to form distorted CaO4 trigonal pyramids that share corners with two equivalent Ti(4)O5 trigonal bipyramids, corners with two equivalent Ca(1)O4 trigonal pyramids,  an edgeedge with one Ti(2)O5 trigonal bipyramid, and edges with two equivalent Ti(1)O4 trigonal pyramids. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one O(5), two equivalent O(1), and two equivalent O(8) atoms. In the third Ca site, Ca(3) is bonded in a distorted T-shaped geometry to one O(5) and two equivalent O(6) atoms. In the fourth Ca site, Ca(4) is bonded in a 6-coordinate geometry to one O(3), one O(7), two equivalent O(2), and two equivalent O(8) atoms. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(5), one O(7), and two equivalent O(4) atoms to form TiO4 trigonal pyramids that share corners with two equivalent Ti(2)O5 trigonal bipyramids, corners with two equivalent Ti(1)O4 trigonal pyramids,  an edgeedge with one Ti(4)O5 trigonal bipyramid, and edges with two equivalent Ca(1)O4 trigonal pyramids. In the second Ti site, Ti(2) is bonded to one O(4), one O(6), one O(8), and two equivalent O(3) atoms to form TiO5 trigonal bipyramids that share corners with two equivalent Ti(2)O5 trigonal bipyramids, corners with two equivalent Ti(1)O4 trigonal pyramids, and  an edgeedge with one Ca(1)O4 trigonal pyramid. In the third Ti site, Ti(3) is bonded in a T-shaped geometry to one O(1), one O(6), and one O(8) atom. In the fourth Ti site, Ti(4) is bonded to one O(1), one O(5), one O(7), and two equivalent O(2) atoms to form distorted TiO5 trigonal bipyramids that share corners with two equivalent Ti(4)O5 trigonal bipyramids, corners with two equivalent Ca(1)O4 trigonal pyramids, and  an edgeedge with one Ti(1)O4 trigonal pyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(2), one Ti(3), and one Ti(4) atom to form OCa2Ti2 trigonal pyramids that share  a cornercorner with one O(6)Ca3Ti2 trigonal bipyramid,  a cornercorner with one O(7)Ca3Ti2 trigonal bipyramid, and corners with two equivalent O(1)Ca2Ti2 trigonal pyramids. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca(4) and two equivalent Ti(4) atoms. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Ca(4) and two equivalent Ti(2) atoms. In the fourth O site, O(4) is bonded to one Ca(1), one Ti(2), and two equivalent Ti(1) atoms to form OCaTi3 trigonal pyramids that share corners with two equivalent O(4)CaTi3 trigonal pyramids,  an edgeedge with one O(6)Ca3Ti2 trigonal bipyramid, and edges with two equivalent O(7)Ca3Ti2 trigonal bipyramids. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Ca(2), one Ca(3), one Ti(1), and one Ti(4) atom. In the sixth O site, O(6) is bonded to one Ca(1), two equivalent Ca(3), one Ti(2), and one Ti(3) atom to form OCa3Ti2 trigonal bipyramids that share corners with two equivalent O(6)Ca3Ti2 trigonal bipyramids, corners with two equivalent O(7)Ca3Ti2 trigonal bipyramids,  a cornercorner with one O(1)Ca2Ti2 trigonal pyramid, and  an edgeedge with one O(4)CaTi3 trigonal pyramid. In the seventh O site, O(7) is bonded to one Ca(4), two equivalent Ca(1), one Ti(1), and one Ti(4) atom to form distorted OCa3Ti2 trigonal bipyramids that share corners with two equivalent O(6)Ca3Ti2 trigonal bipyramids, corners with two equivalent O(7)Ca3Ti2 trigonal bipyramids,  a cornercorner with one O(1)Ca2Ti2 trigonal pyramid, and edges with two equivalent O(4)CaTi3 trigonal pyramids. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to two equivalent Ca(2), two equivalent Ca(4), one Ti(2), and one Ti(3) atom.
CaTiO2 crystallizes in the triclinic P1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(4), one O(6), and two equivalent O(7) atoms to form distorted CaO4 trigonal pyramids that share corners with two equivalent Ti(4)O5 trigonal bipyramids, corners with two equivalent Ca(1)O4 trigonal pyramids,  an edgeedge with one Ti(2)O5 trigonal bipyramid, and edges with two equivalent Ti(1)O4 trigonal pyramids. The Ca(1)-O(4) bond length is 2.42 Å. The Ca(1)-O(6) bond length is 2.42 Å. There is one shorter (2.26 Å) and one longer (2.30 Å) Ca(1)-O(7) bond length. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one O(5), two equivalent O(1), and two equivalent O(8) atoms. The Ca(2)-O(5) bond length is 2.39 Å. There is one shorter (2.31 Å) and one longer (2.34 Å) Ca(2)-O(1) bond length. There is one shorter (2.87 Å) and one longer (2.89 Å) Ca(2)-O(8) bond length. In the third Ca site, Ca(3) is bonded in a distorted T-shaped geometry to one O(5) and two equivalent O(6) atoms. The Ca(3)-O(5) bond length is 2.55 Å. There is one shorter (2.46 Å) and one longer (2.48 Å) Ca(3)-O(6) bond length. In the fourth Ca site, Ca(4) is bonded in a 6-coordinate geometry to one O(3), one O(7), two equivalent O(2), and two equivalent O(8) atoms. The Ca(4)-O(3) bond length is 2.25 Å. The Ca(4)-O(7) bond length is 2.64 Å. There is one shorter (2.51 Å) and one longer (2.52 Å) Ca(4)-O(2) bond length. There is one shorter (2.41 Å) and one longer (2.45 Å) Ca(4)-O(8) bond length. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(5), one O(7), and two equivalent O(4) atoms to form TiO4 trigonal pyramids that share corners with two equivalent Ti(2)O5 trigonal bipyramids, corners with two equivalent Ti(1)O4 trigonal pyramids,  an edgeedge with one Ti(4)O5 trigonal bipyramid, and edges with two equivalent Ca(1)O4 trigonal pyramids. The Ti(1)-O(5) bond length is 2.02 Å. The Ti(1)-O(7) bond length is 2.02 Å. There is one shorter (1.90 Å) and one longer (1.98 Å) Ti(1)-O(4) bond length. In the second Ti site, Ti(2) is bonded to one O(4), one O(6), one O(8), and two equivalent O(3) atoms to form TiO5 trigonal bipyramids that share corners with two equivalent Ti(2)O5 trigonal bipyramids, corners with two equivalent Ti(1)O4 trigonal pyramids, and  an edgeedge with one Ca(1)O4 trigonal pyramid. The Ti(2)-O(4) bond length is 2.14 Å. The Ti(2)-O(6) bond length is 2.01 Å. The Ti(2)-O(8) bond length is 2.12 Å. There is one shorter (1.90 Å) and one longer (1.92 Å) Ti(2)-O(3) bond length. In the third Ti site, Ti(3) is bonded in a T-shaped geometry to one O(1), one O(6), and one O(8) atom. The Ti(3)-O(1) bond length is 1.95 Å. The Ti(3)-O(6) bond length is 2.08 Å. The Ti(3)-O(8) bond length is 1.94 Å. In the fourth Ti site, Ti(4) is bonded to one O(1), one O(5), one O(7), and two equivalent O(2) atoms to form distorted TiO5 trigonal bipyramids that share corners with two equivalent Ti(4)O5 trigonal bipyramids, corners with two equivalent Ca(1)O4 trigonal pyramids, and  an edgeedge with one Ti(1)O4 trigonal pyramid. The Ti(4)-O(1) bond length is 1.98 Å. The Ti(4)-O(5) bond length is 2.00 Å. The Ti(4)-O(7) bond length is 2.00 Å. There is one shorter (1.86 Å) and one longer (2.22 Å) Ti(4)-O(2) bond length. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Ca(2), one Ti(3), and one Ti(4) atom to form OCa2Ti2 trigonal pyramids that share  a cornercorner with one O(6)Ca3Ti2 trigonal bipyramid,  a cornercorner with one O(7)Ca3Ti2 trigonal bipyramid, and corners with two equivalent O(1)Ca2Ti2 trigonal pyramids. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca(4) and two equivalent Ti(4) atoms. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Ca(4) and two equivalent Ti(2) atoms. In the fourth O site, O(4) is bonded to one Ca(1), one Ti(2), and two equivalent Ti(1) atoms to form OCaTi3 trigonal pyramids that share corners with two equivalent O(4)CaTi3 trigonal pyramids,  an edgeedge with one O(6)Ca3Ti2 trigonal bipyramid, and edges with two equivalent O(7)Ca3Ti2 trigonal bipyramids. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Ca(2), one Ca(3), one Ti(1), and one Ti(4) atom. In the sixth O site, O(6) is bonded to one Ca(1), two equivalent Ca(3), one Ti(2), and one Ti(3) atom to form OCa3Ti2 trigonal bipyramids that share corners with two equivalent O(6)Ca3Ti2 trigonal bipyramids, corners with two equivalent O(7)Ca3Ti2 trigonal bipyramids,  a cornercorner with one O(1)Ca2Ti2 trigonal pyramid, and  an edgeedge with one O(4)CaTi3 trigonal pyramid. In the seventh O site, O(7) is bonded to one Ca(4), two equivalent Ca(1), one Ti(1), and one Ti(4) atom to form distorted OCa3Ti2 trigonal bipyramids that share corners with two equivalent O(6)Ca3Ti2 trigonal bipyramids, corners with two equivalent O(7)Ca3Ti2 trigonal bipyramids,  a cornercorner with one O(1)Ca2Ti2 trigonal pyramid, and edges with two equivalent O(4)CaTi3 trigonal pyramids. In the eighth O site, O(8) is bonded in a 6-coordinate geometry to two equivalent Ca(2), two equivalent Ca(4), one Ti(2), and one Ti(3) atom.