Ca3Ti2O7 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(4), and four equivalent O(2) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(2), two equivalent O(1), and three equivalent O(3) atoms. Ti(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 22-26°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), and two equivalent Ti(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Ca(2) and one Ti(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Ca(1) and two equivalent Ti(1) atoms.
Ca3Ti2O7 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(4), and four equivalent O(2) atoms. Both Ca(1)-O(1) bond lengths are 2.65 Å. There is one shorter (2.36 Å) and one longer (2.47 Å) Ca(1)-O(4) bond length. There are two shorter (2.40 Å) and two longer (2.64 Å) Ca(1)-O(2) bond lengths. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(2), two equivalent O(1), and three equivalent O(3) atoms. The Ca(2)-O(2) bond length is 2.47 Å. There is one shorter (2.33 Å) and one longer (2.57 Å) Ca(2)-O(1) bond length. There are a spread of Ca(2)-O(3) bond distances ranging from 2.29-2.44 Å. Ti(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 22-26°. The Ti(1)-O(3) bond length is 1.94 Å. The Ti(1)-O(4) bond length is 1.97 Å. There is one shorter (1.93 Å) and one longer (1.98 Å) Ti(1)-O(1) bond length. There is one shorter (1.94 Å) and one longer (2.00 Å) Ti(1)-O(2) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ca(2), two equivalent Ca(1), and two equivalent Ti(1) atoms. In the third O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Ca(2) and one Ti(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to two equivalent Ca(1) and two equivalent Ti(1) atoms.