data_Ca2TaCu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.59
_cell_length_b   4.59
_cell_length_c   4.51
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca2TaCu
_chemical_formula_sum   'Ca2 Ta1 Cu1'
_cell_volume   94.94
_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  0.29  0.0  0.26  1.0
  Ca  Ca1  1  0.0  0.29  0.26  1.0
  Ta  Ta3  1  0.29  0.29  0.0  1.0
  Cu  Cu2  1  0.0  0.0  0.0  1.0

data_Ca2TaCu
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.49
_cell_length_b   6.49
_cell_length_c   4.51
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Ca2TaCu
_chemical_formula_sum   'Ca4 Ta2 Cu2'
_cell_volume   189.88
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  4  0.15  0.15  0.26  1.0
  Ta  Ta1  2  0.29  0.0  -0.0  1.0
  Cu  Cu2  2  0.0  0.0  0.0  1.0

Ca Ca Ta Cu
Ca2TaCu is alpha Po structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two Ca2TaCu clusters. Ca(1) is bonded in a 2-coordinate geometry to one Ta(1) and one Cu(1) atom. The Ca(1)-Ta(1) bond length is 1.77 Å. The Ca(1)-Cu(1) bond length is 1.77 Å. Ta(1) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one Cu(1) atom. The Ta(1)-Cu(1) bond length is 1.90 Å. Cu(1) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one Ta(1) atom.