data_Ca2TaTi
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.18
_cell_length_b   5.18
_cell_length_c   5.18
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca2TaTi
_chemical_formula_sum   'Ca2 Ta1 Ti1'
_cell_volume   98.44
_cell_formula_units_Z   1
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  0.83  0.83  0.83  1.0
  Ca  Ca1  1  0.0  0.0  0.0  1.0
  Ta  Ta2  1  0.5  0.5  0.5  1.0
  Ti  Ti3  1  0.66  0.66  0.66  1.0

data_Ca2TaTi
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.18
_cell_length_b   5.18
_cell_length_c   12.7
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Ca2TaTi
_chemical_formula_sum   'Ca6 Ta3 Ti3'
_cell_volume   295.31
_cell_formula_units_Z   3
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.0  1.0
  Ca  Ca1  3  0.0  0.0  0.17  1.0
  Ta  Ta2  3  0.0  0.0  0.5  1.0
  Ti  Ti3  3  0.0  0.0  0.34  1.0

Ca Ca Ta Ti
Ca Ca Ta Ti 0 3 o o o 0 1 + + + 2 3 o o o 
Ca2TiTa crystallizes in the trigonal R3m space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted single-bond geometry to one Ca(2), one Ti(1), and three equivalent Ta(1) atoms. The Ca(1)-Ca(2) bond length is 2.13 Å. The Ca(1)-Ti(1) bond length is 2.13 Å. All Ca(1)-Ta(1) bond lengths are 2.99 Å. In the second Ca site, Ca(2) is bonded to one Ca(1), three equivalent Ti(1), and three equivalent Ta(1) atoms to form distorted CaCaTa3Ti3 trigonal pyramids that share corners with four equivalent Ti(1)Ca4Ta trigonal bipyramids, edges with three equivalent Ta(1)Ca6Ti trigonal pyramids, and edges with six equivalent Ca(2)CaTa3Ti3 trigonal pyramids. All Ca(2)-Ti(1) bond lengths are 2.99 Å. All Ca(2)-Ta(1) bond lengths are 3.64 Å. Ti(1) is bonded to one Ca(1), three equivalent Ca(2), and one Ta(1) atom to form distorted TiCa4Ta trigonal bipyramids that share corners with six equivalent Ti(1)Ca4Ta trigonal bipyramids, corners with three equivalent Ta(1)Ca6Ti trigonal pyramids, corners with four equivalent Ca(2)CaTa3Ti3 trigonal pyramids, and faces with three equivalent Ta(1)Ca6Ti trigonal pyramids. The Ti(1)-Ta(1) bond length is 2.13 Å. Ta(1) is bonded to three equivalent Ca(1), three equivalent Ca(2), and one Ti(1) atom to form distorted TaCa6Ti trigonal pyramids that share corners with three equivalent Ti(1)Ca4Ta trigonal bipyramids, edges with three equivalent Ca(2)CaTa3Ti3 trigonal pyramids, edges with six equivalent Ta(1)Ca6Ti trigonal pyramids, and faces with three equivalent Ti(1)Ca4Ta trigonal bipyramids.