data_CaMg2Cu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.26
_cell_length_b   8.26
_cell_length_c   8.26
_cell_angle_alpha   145.29
_cell_angle_beta   145.29
_cell_angle_gamma   49.9
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaMg2Cu
_chemical_formula_sum   'Ca2 Mg4 Cu2'
_cell_volume   181.65
_cell_formula_units_Z   2
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  0.46  0.74  1.0
  Ca  Ca1  1  0.46  0.0  0.74  1.0
  Mg  Mg4  1  0.0  0.46  0.0  1.0
  Mg  Mg5  1  0.46  0.0  0.0  1.0
  Mg  Mg6  1  0.0  0.0  0.87  1.0
  Mg  Mg7  1  0.0  0.0  0.1  1.0
  Cu  Cu2  1  0.0  0.0  0.59  1.0
  Cu  Cu3  1  0.0  0.0  0.38  1.0

data_CaMg2Cu
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.97
_cell_length_b   6.97
_cell_length_c   8.26
_cell_angle_alpha   90.0
_cell_angle_beta   114.95
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   CaMg2Cu
_chemical_formula_sum   'Ca4 Mg8 Cu4'
_cell_volume   363.31
_cell_formula_units_Z   4
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  0.01  0.27  0.28  1.0
  Mg  Mg1  4  0.27  0.73  0.54  1.0
  Mg  Mg2  2  0.1  0.0  0.1  1.0
  Mg  Mg3  2  0.37  0.5  0.87  1.0
  Cu  Cu4  2  0.09  0.5  0.59  1.0
  Cu  Cu5  2  0.38  0.0  0.38  1.0

Ca Ca Mg Mg Mg Mg Cu Cu
CaMg2Cu crystallizes in the monoclinic Cm space group. Ca(1) is bonded in a 3-coordinate geometry to one Mg(1), one Mg(3), and one Cu(2) atom. The Ca(1)-Mg(1) bond length is 2.12 Å. The Ca(1)-Mg(3) bond length is 2.61 Å. The Ca(1)-Cu(2) bond length is 2.18 Å. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 4-coordinate geometry to one Ca(1), one Cu(2), and two equivalent Cu(1) atoms. The Mg(1)-Cu(2) bond length is 2.58 Å. There is one shorter (2.19 Å) and one longer (2.83 Å) Mg(1)-Cu(1) bond length. In the second Mg site, Mg(2) is bonded in a distorted linear geometry to one Mg(3) and one Cu(1) atom. The Mg(2)-Mg(3) bond length is 1.94 Å. The Mg(2)-Cu(1) bond length is 2.26 Å. In the third Mg site, Mg(3) is bonded in a 1-coordinate geometry to two equivalent Ca(1), one Mg(2), and one Cu(2) atom. The Mg(3)-Cu(2) bond length is 2.26 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 6-coordinate geometry to one Mg(2), four equivalent Mg(1), and one Cu(2) atom. The Cu(1)-Cu(2) bond length is 1.79 Å. In the second Cu site, Cu(2) is bonded in a 6-coordinate geometry to two equivalent Ca(1), one Mg(3), two equivalent Mg(1), and one Cu(1) atom.