data_Ca3Cr
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.43
_cell_length_b   6.43
_cell_length_c   6.43
_cell_angle_alpha   117.03
_cell_angle_beta   117.03
_cell_angle_gamma   117.03
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca3Cr
_chemical_formula_sum   'Ca3 Cr1'
_cell_volume   116.47
_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  0.0  0.16  0.12  1.0
  Ca  Ca1  1  0.74  0.42  0.12  1.0
  Ca  Ca2  1  0.26  0.42  0.12  1.0
  Cr  Cr3  1  0.0  0.0  0.0  1.0

data_Ca3Cr
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.36
_cell_length_b   6.43
_cell_length_c   6.43
_cell_angle_alpha   117.03
_cell_angle_beta   100.03
_cell_angle_gamma   100.03
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca3Cr
_chemical_formula_sum   'Ca3 Cr1'
_cell_volume   116.47
_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  0.12  0.38  0.7  1.0
  Ca  Ca1  1  0.12  0.86  0.7  1.0
  Ca  Ca2  1  0.12  0.12  0.96  1.0
  Cr  Cr3  1  0.0  0.0  0.0  1.0

Ca Ca Ca Cr
Ca Ca Ca Cr 0 3 o o o 0 1 - o o 0 2 o o o 1 1 + + + 1 3 o o o 1 3 + o o 1 2 o o o 1 2 + o o 2 3 o o o 
Ca3Cr crystallizes in the triclinic P1 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a single-bond geometry to one Ca(2) and one Cr(1) atom. The Ca(1)-Ca(2) bond length is 2.81 Å. The Ca(1)-Cr(1) bond length is 0.98 Å. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one Ca(1), two equivalent Ca(2), two equivalent Ca(3), and three equivalent Cr(1) atoms. Both Ca(2)-Ca(2) bond lengths are 3.36 Å. There is one shorter (3.09 Å) and one longer (3.34 Å) Ca(2)-Ca(3) bond length. There are a spread of Ca(2)-Cr(1) bond distances ranging from 3.69-3.93 Å. In the third Ca site, Ca(3) is bonded in a 1-coordinate geometry to two equivalent Ca(2) and one Cr(1) atom. The Ca(3)-Cr(1) bond length is 1.86 Å. Cr(1) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(3), and three equivalent Ca(2) atoms.