Ca3TiNiO6 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(1), and two equivalent O(3) atoms. Ti(1) is bonded in a 4-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Ni(1) is bonded in a 4-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca(2), one Ti(1), and one Ni(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(2), one Ti(1), and one Ni(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Ti(1), and one Ni(1) atom.
Ca3TiNiO6 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(3) atoms. Both Ca(1)-O(2) bond lengths are 2.34 Å. There are two shorter (2.04 Å) and two longer (2.83 Å) Ca(1)-O(3) bond lengths. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(1), and two equivalent O(3) atoms. The Ca(2)-O(2) bond length is 2.33 Å. There is one shorter (2.11 Å) and one longer (2.30 Å) Ca(2)-O(1) bond length. There is one shorter (2.27 Å) and one longer (2.73 Å) Ca(2)-O(3) bond length. Ti(1) is bonded in a 4-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Both Ti(1)-O(1) bond lengths are 2.01 Å. Both Ti(1)-O(2) bond lengths are 1.78 Å. Both Ti(1)-O(3) bond lengths are 2.45 Å. Ni(1) is bonded in a 4-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Both Ni(1)-O(1) bond lengths are 2.17 Å. Both Ni(1)-O(2) bond lengths are 1.95 Å. Both Ni(1)-O(3) bond lengths are 2.58 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ca(2), one Ti(1), and one Ni(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(2), one Ti(1), and one Ni(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Ca(1), two equivalent Ca(2), one Ti(1), and one Ni(1) atom.