The compound described by CaTi2O4 is Spinel-like structured and crystallizes in the trigonal P3m1 space group. There are six inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(10) and three equivalent O(1) atoms to form CaO4 tetrahedra that share corners with three equivalent Ca(3)O6 octahedra, corners with three equivalent Ti(4)O6 octahedra, and corners with six equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-70°. In the second Ca site, Ca(2) is bonded to one O(2) and three equivalent O(4) atoms to form CaO4 tetrahedra that share corners with three equivalent Ti(1)O6 octahedra, corners with three equivalent Ti(3)O6 octahedra, and corners with six equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 60-61°. In the third Ca site, Ca(3) is bonded to three equivalent O(1) and three equivalent O(11) atoms to form CaO6 octahedra that share corners with three equivalent Ca(1)O4 tetrahedra, corners with three equivalent Ti(6)O4 tetrahedra, edges with three equivalent Ti(1)O6 octahedra, and edges with three equivalent Ti(4)O6 octahedra. In the fourth Ca site, Ca(4) is bonded to one O(6) and three equivalent O(8) atoms to form CaO4 tetrahedra that share corners with three equivalent Ti(2)O6 octahedra, corners with three equivalent Ti(5)O6 octahedra, and corners with six equivalent Ti(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 60-61°. In the fifth Ca site, Ca(5) is bonded to one O(9) and three equivalent O(3) atoms to form CaO4 tetrahedra that share corners with three equivalent Ti(2)O6 octahedra, corners with three equivalent Ti(3)O6 octahedra, and corners with six equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 59-62°. In the sixth Ca site, Ca(6) is bonded to one O(12) and three equivalent O(7) atoms to form CaO4 tetrahedra that share corners with three equivalent Ti(4)O6 octahedra, corners with three equivalent Ti(5)O6 octahedra, and corners with six equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 59-64°. There are six inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form TiO6 octahedra that share  a cornercorner with one Ca(2)O4 tetrahedra,  a cornercorner with one Ti(6)O4 tetrahedra, corners with two equivalent Ca(1)O4 tetrahedra, corners with two equivalent Ca(5)O4 tetrahedra,  an edgeedge with one Ca(3)O6 octahedra,  an edgeedge with one Ti(3)O6 octahedra, and edges with four equivalent Ti(1)O6 octahedra. In the second Ti site, Ti(2) is bonded to one O(6), one O(9), two equivalent O(4), and two equivalent O(7) atoms to form TiO6 octahedra that share  a cornercorner with one Ca(4)O4 tetrahedra,  a cornercorner with one Ca(5)O4 tetrahedra, corners with two equivalent Ca(2)O4 tetrahedra, corners with two equivalent Ca(6)O4 tetrahedra,  an edgeedge with one Ti(3)O6 octahedra,  an edgeedge with one Ti(5)O6 octahedra, and edges with four equivalent Ti(2)O6 octahedra. In the third Ti site, Ti(3) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form TiO6 octahedra that share corners with three equivalent Ca(2)O4 tetrahedra, corners with three equivalent Ca(5)O4 tetrahedra, edges with three equivalent Ti(1)O6 octahedra, and edges with three equivalent Ti(2)O6 octahedra. In the fourth Ti site, Ti(4) is bonded to one O(10), one O(12), two equivalent O(11), and two equivalent O(8) atoms to form TiO6 octahedra that share  a cornercorner with one Ca(1)O4 tetrahedra,  a cornercorner with one Ca(6)O4 tetrahedra, corners with two equivalent Ca(4)O4 tetrahedra, corners with two equivalent Ti(6)O4 tetrahedra,  an edgeedge with one Ca(3)O6 octahedra,  an edgeedge with one Ti(5)O6 octahedra, and edges with four equivalent Ti(4)O6 octahedra. In the fifth Ti site, Ti(5) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form TiO6 octahedra that share corners with three equivalent Ca(4)O4 tetrahedra, corners with three equivalent Ca(6)O4 tetrahedra, edges with three equivalent Ti(2)O6 octahedra, and edges with three equivalent Ti(4)O6 octahedra. In the sixth Ti site, Ti(6) is bonded to one O(5) and three equivalent O(11) atoms to form TiO4 tetrahedra that share corners with three equivalent Ca(3)O6 octahedra, corners with three equivalent Ti(1)O6 octahedra, and corners with six equivalent Ti(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-61°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(3), and two equivalent Ti(1) atoms to form OCa2Ti2 trigonal pyramids that share corners with four equivalent O(3)CaTi3 tetrahedra, corners with two equivalent O(1)Ca2Ti2 trigonal pyramids,  an edgeedge with one O(2)CaTi3 tetrahedra, and edges with two equivalent O(1)Ca2Ti2 trigonal pyramids. In the second O site, O(2) is bonded to one Ca(2) and three equivalent Ti(1) atoms to form OCaTi3 tetrahedra that share corners with three equivalent O(4)CaTi3 tetrahedra, corners with six equivalent O(3)CaTi3 tetrahedra, and edges with three equivalent O(1)Ca2Ti2 trigonal pyramids. In the third O site, O(3) is bonded to one Ca(5), one Ti(3), and two equivalent Ti(1) atoms to form OCaTi3 tetrahedra that share  a cornercorner with one O(9)CaTi3 tetrahedra, corners with two equivalent O(2)CaTi3 tetrahedra, corners with two equivalent O(3)CaTi3 tetrahedra, corners with three equivalent O(4)CaTi3 tetrahedra, corners with four equivalent O(1)Ca2Ti2 trigonal pyramids, and edges with two equivalent O(3)CaTi3 tetrahedra. In the fourth O site, O(4) is bonded to one Ca(2), one Ti(3), and two equivalent Ti(2) atoms to form a mixture of distorted corner and edge-sharing OCaTi3 tetrahedra. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Ti(6) and three equivalent Ti(1) atoms. In the sixth O site, O(6) is bonded to one Ca(4) and three equivalent Ti(2) atoms to form a mixture of distorted corner and edge-sharing OCaTi3 tetrahedra. In the seventh O site, O(7) is bonded to one Ca(6), one Ti(5), and two equivalent Ti(2) atoms to form a mixture of distorted corner and edge-sharing OCaTi3 trigonal pyramids. In the eighth O site, O(8) is bonded to one Ca(4), one Ti(5), and two equivalent Ti(4) atoms to form a mixture of distorted corner and edge-sharing OCaTi3 tetrahedra. In the ninth O site, O(9) is bonded to one Ca(5) and three equivalent Ti(2) atoms to form a mixture of distorted corner and edge-sharing OCaTi3 tetrahedra. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1) and three equivalent Ti(4) atoms. In the eleventh O site, O(11) is bonded in a rectangular see-saw-like geometry to one Ca(3), one Ti(6), and two equivalent Ti(4) atoms. In the twelfth O site, O(12) is bonded to one Ca(6) and three equivalent Ti(4) atoms to form corner-sharing OCaTi3 tetrahedra. is represented by the CIF file [CIF]
data_CaTi2O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.255
_cell_length_b   6.255
_cell_length_c   15.554
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   526.983
_cell_formula_units_Z   6
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ca  Ca0  1  0.667  0.333  0.043  1.0
  Ca  Ca1  1  0.333  0.667  0.374  1.0
  Ca  Ca2  1  0.333  0.667  0.002  1.0
  Ca  Ca3  1  0.000  0.000  0.708  1.0
  Ca  Ca4  1  0.667  0.333  0.289  1.0
  Ca  Ca5  1  0.333  0.667  0.628  1.0
  Ti  Ti6  1  0.161  0.839  0.169  1.0
  Ti  Ti7  1  0.679  0.839  0.169  1.0
  Ti  Ti8  1  0.832  0.168  0.500  1.0
  Ti  Ti9  1  0.161  0.321  0.169  1.0
  Ti  Ti10  1  0.000  0.000  0.341  1.0
  Ti  Ti11  1  0.336  0.168  0.500  1.0
  Ti  Ti12  1  0.506  0.494  0.829  1.0
  Ti  Ti13  1  0.832  0.664  0.500  1.0
  Ti  Ti14  1  0.506  0.013  0.829  1.0
  Ti  Ti15  1  0.667  0.333  0.660  1.0
  Ti  Ti16  1  0.987  0.494  0.829  1.0
  Ti  Ti17  1  0.000  0.000  0.951  1.0
  O  O18  1  0.028  0.514  0.104  1.0
  O  O19  1  0.333  0.667  0.234  1.0
  O  O20  1  0.486  0.972  0.104  1.0
  O  O21  1  0.486  0.514  0.104  1.0
  O  O22  1  0.860  0.140  0.249  1.0
  O  O23  1  0.710  0.855  0.424  1.0
  O  O24  1  0.860  0.719  0.249  1.0
  O  O25  1  0.000  0.000  0.080  1.0
  O  O26  1  0.145  0.290  0.424  1.0
  O  O27  1  0.000  0.000  0.566  1.0
  O  O28  1  0.281  0.140  0.249  1.0
  O  O29  1  0.145  0.855  0.424  1.0
  O  O30  1  0.521  0.479  0.577  1.0
  O  O31  1  0.381  0.190  0.751  1.0
  O  O32  1  0.521  0.042  0.577  1.0
  O  O33  1  0.667  0.333  0.433  1.0
  O  O34  1  0.667  0.333  0.901  1.0
  O  O35  1  0.810  0.619  0.751  1.0
  O  O36  1  0.958  0.479  0.577  1.0
  O  O37  1  0.810  0.190  0.751  1.0
  O  O38  1  0.162  0.838  0.905  1.0
  O  O39  1  0.333  0.667  0.769  1.0
  O  O40  1  0.162  0.325  0.905  1.0
  O  O41  1  0.675  0.838  0.905  1.0
[/CIF]
.
The compound described by CaTi2O4 is Spinel-like structured and crystallizes in the trigonal P3m1 space group. There are six inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(10) and three equivalent O(1) atoms to form CaO4 tetrahedra that share corners with three equivalent Ca(3)O6 octahedra, corners with three equivalent Ti(4)O6 octahedra, and corners with six equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-70°. In the second Ca site, Ca(2) is bonded to one O(2) and three equivalent O(4) atoms to form CaO4 tetrahedra that share corners with three equivalent Ti(1)O6 octahedra, corners with three equivalent Ti(3)O6 octahedra, and corners with six equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 60-61°. In the third Ca site, Ca(3) is bonded to three equivalent O(1) and three equivalent O(11) atoms to form CaO6 octahedra that share corners with three equivalent Ca(1)O4 tetrahedra, corners with three equivalent Ti(6)O4 tetrahedra, edges with three equivalent Ti(1)O6 octahedra, and edges with three equivalent Ti(4)O6 octahedra. In the fourth Ca site, Ca(4) is bonded to one O(6) and three equivalent O(8) atoms to form CaO4 tetrahedra that share corners with three equivalent Ti(2)O6 octahedra, corners with three equivalent Ti(5)O6 octahedra, and corners with six equivalent Ti(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 60-61°. In the fifth Ca site, Ca(5) is bonded to one O(9) and three equivalent O(3) atoms to form CaO4 tetrahedra that share corners with three equivalent Ti(2)O6 octahedra, corners with three equivalent Ti(3)O6 octahedra, and corners with six equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 59-62°. In the sixth Ca site, Ca(6) is bonded to one O(12) and three equivalent O(7) atoms to form CaO4 tetrahedra that share corners with three equivalent Ti(4)O6 octahedra, corners with three equivalent Ti(5)O6 octahedra, and corners with six equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 59-64°. There are six inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(2), one O(5), two equivalent O(1), and two equivalent O(3) atoms to form TiO6 octahedra that share  a cornercorner with one Ca(2)O4 tetrahedra,  a cornercorner with one Ti(6)O4 tetrahedra, corners with two equivalent Ca(1)O4 tetrahedra, corners with two equivalent Ca(5)O4 tetrahedra,  an edgeedge with one Ca(3)O6 octahedra,  an edgeedge with one Ti(3)O6 octahedra, and edges with four equivalent Ti(1)O6 octahedra. In the second Ti site, Ti(2) is bonded to one O(6), one O(9), two equivalent O(4), and two equivalent O(7) atoms to form TiO6 octahedra that share  a cornercorner with one Ca(4)O4 tetrahedra,  a cornercorner with one Ca(5)O4 tetrahedra, corners with two equivalent Ca(2)O4 tetrahedra, corners with two equivalent Ca(6)O4 tetrahedra,  an edgeedge with one Ti(3)O6 octahedra,  an edgeedge with one Ti(5)O6 octahedra, and edges with four equivalent Ti(2)O6 octahedra. In the third Ti site, Ti(3) is bonded to three equivalent O(3) and three equivalent O(4) atoms to form TiO6 octahedra that share corners with three equivalent Ca(2)O4 tetrahedra, corners with three equivalent Ca(5)O4 tetrahedra, edges with three equivalent Ti(1)O6 octahedra, and edges with three equivalent Ti(2)O6 octahedra. In the fourth Ti site, Ti(4) is bonded to one O(10), one O(12), two equivalent O(11), and two equivalent O(8) atoms to form TiO6 octahedra that share  a cornercorner with one Ca(1)O4 tetrahedra,  a cornercorner with one Ca(6)O4 tetrahedra, corners with two equivalent Ca(4)O4 tetrahedra, corners with two equivalent Ti(6)O4 tetrahedra,  an edgeedge with one Ca(3)O6 octahedra,  an edgeedge with one Ti(5)O6 octahedra, and edges with four equivalent Ti(4)O6 octahedra. In the fifth Ti site, Ti(5) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form TiO6 octahedra that share corners with three equivalent Ca(4)O4 tetrahedra, corners with three equivalent Ca(6)O4 tetrahedra, edges with three equivalent Ti(2)O6 octahedra, and edges with three equivalent Ti(4)O6 octahedra. In the sixth Ti site, Ti(6) is bonded to one O(5) and three equivalent O(11) atoms to form TiO4 tetrahedra that share corners with three equivalent Ca(3)O6 octahedra, corners with three equivalent Ti(1)O6 octahedra, and corners with six equivalent Ti(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-61°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to one Ca(1), one Ca(3), and two equivalent Ti(1) atoms to form OCa2Ti2 trigonal pyramids that share corners with four equivalent O(3)CaTi3 tetrahedra, corners with two equivalent O(1)Ca2Ti2 trigonal pyramids,  an edgeedge with one O(2)CaTi3 tetrahedra, and edges with two equivalent O(1)Ca2Ti2 trigonal pyramids. In the second O site, O(2) is bonded to one Ca(2) and three equivalent Ti(1) atoms to form OCaTi3 tetrahedra that share corners with three equivalent O(4)CaTi3 tetrahedra, corners with six equivalent O(3)CaTi3 tetrahedra, and edges with three equivalent O(1)Ca2Ti2 trigonal pyramids. In the third O site, O(3) is bonded to one Ca(5), one Ti(3), and two equivalent Ti(1) atoms to form OCaTi3 tetrahedra that share  a cornercorner with one O(9)CaTi3 tetrahedra, corners with two equivalent O(2)CaTi3 tetrahedra, corners with two equivalent O(3)CaTi3 tetrahedra, corners with three equivalent O(4)CaTi3 tetrahedra, corners with four equivalent O(1)Ca2Ti2 trigonal pyramids, and edges with two equivalent O(3)CaTi3 tetrahedra. In the fourth O site, O(4) is bonded to one Ca(2), one Ti(3), and two equivalent Ti(2) atoms to form a mixture of distorted corner and edge-sharing OCaTi3 tetrahedra. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to one Ti(6) and three equivalent Ti(1) atoms. In the sixth O site, O(6) is bonded to one Ca(4) and three equivalent Ti(2) atoms to form a mixture of distorted corner and edge-sharing OCaTi3 tetrahedra. In the seventh O site, O(7) is bonded to one Ca(6), one Ti(5), and two equivalent Ti(2) atoms to form a mixture of distorted corner and edge-sharing OCaTi3 trigonal pyramids. In the eighth O site, O(8) is bonded to one Ca(4), one Ti(5), and two equivalent Ti(4) atoms to form a mixture of distorted corner and edge-sharing OCaTi3 tetrahedra. In the ninth O site, O(9) is bonded to one Ca(5) and three equivalent Ti(2) atoms to form a mixture of distorted corner and edge-sharing OCaTi3 tetrahedra. In the tenth O site, O(10) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1) and three equivalent Ti(4) atoms. In the eleventh O site, O(11) is bonded in a rectangular see-saw-like geometry to one Ca(3), one Ti(6), and two equivalent Ti(4) atoms. In the twelfth O site, O(12) is bonded to one Ca(6) and three equivalent Ti(4) atoms to form corner-sharing OCaTi3 tetrahedra. is represented by the CIF file [CIF]
data_CaTi2O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.255
_cell_length_b   6.255
_cell_length_c   15.554
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   526.983
_cell_formula_units_Z   6
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Ca  Ca0  1  0.667  0.333  0.043  1.0
  Ca  Ca1  1  0.333  0.667  0.374  1.0
  Ca  Ca2  1  0.333  0.667  0.002  1.0
  Ca  Ca3  1  0.000  0.000  0.708  1.0
  Ca  Ca4  1  0.667  0.333  0.289  1.0
  Ca  Ca5  1  0.333  0.667  0.628  1.0
  Ti  Ti6  1  0.161  0.839  0.169  1.0
  Ti  Ti7  1  0.679  0.839  0.169  1.0
  Ti  Ti8  1  0.832  0.168  0.500  1.0
  Ti  Ti9  1  0.161  0.321  0.169  1.0
  Ti  Ti10  1  0.000  0.000  0.341  1.0
  Ti  Ti11  1  0.336  0.168  0.500  1.0
  Ti  Ti12  1  0.506  0.494  0.829  1.0
  Ti  Ti13  1  0.832  0.664  0.500  1.0
  Ti  Ti14  1  0.506  0.013  0.829  1.0
  Ti  Ti15  1  0.667  0.333  0.660  1.0
  Ti  Ti16  1  0.987  0.494  0.829  1.0
  Ti  Ti17  1  0.000  0.000  0.951  1.0
  O  O18  1  0.028  0.514  0.104  1.0
  O  O19  1  0.333  0.667  0.234  1.0
  O  O20  1  0.486  0.972  0.104  1.0
  O  O21  1  0.486  0.514  0.104  1.0
  O  O22  1  0.860  0.140  0.249  1.0
  O  O23  1  0.710  0.855  0.424  1.0
  O  O24  1  0.860  0.719  0.249  1.0
  O  O25  1  0.000  0.000  0.080  1.0
  O  O26  1  0.145  0.290  0.424  1.0
  O  O27  1  0.000  0.000  0.566  1.0
  O  O28  1  0.281  0.140  0.249  1.0
  O  O29  1  0.145  0.855  0.424  1.0
  O  O30  1  0.521  0.479  0.577  1.0
  O  O31  1  0.381  0.190  0.751  1.0
  O  O32  1  0.521  0.042  0.577  1.0
  O  O33  1  0.667  0.333  0.433  1.0
  O  O34  1  0.667  0.333  0.901  1.0
  O  O35  1  0.810  0.619  0.751  1.0
  O  O36  1  0.958  0.479  0.577  1.0
  O  O37  1  0.810  0.190  0.751  1.0
  O  O38  1  0.162  0.838  0.905  1.0
  O  O39  1  0.333  0.667  0.769  1.0
  O  O40  1  0.162  0.325  0.905  1.0
  O  O41  1  0.675  0.838  0.905  1.0
[/CIF]
.