data_CeMg2Ga
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.09
_cell_length_b   5.09
_cell_length_c   5.09
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CeMg2Ga
_chemical_formula_sum   'Ce1 Mg2 Ga1'
_cell_volume   93.3
_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
  Ce  Ce0  1  0.6  0.6  0.6  1.0
  Mg  Mg2  1  0.4  0.4  0.4  1.0
  Mg  Mg3  1  0.8  0.8  0.8  1.0
  Ga  Ga1  1  0.0  0.0  0.0  1.0

data_CeMg2Ga
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.09
_cell_length_b   5.09
_cell_length_c   12.47
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CeMg2Ga
_chemical_formula_sum   'Ce3 Mg6 Ga3'
_cell_volume   279.9
_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
  Ce  Ce0  3  0.0  0.0  0.4  1.0
  Mg  Mg1  3  0.0  0.0  0.2  1.0
  Mg  Mg2  3  0.0  0.0  0.6  1.0
  Ga  Ga3  3  0.0  0.0  0.0  1.0

Ce Mg Mg Ga
Ce Mg Mg Ga 0 1 o o o 0 1 o + o 0 1 + o o 0 1 o o + 0 3 o + + 0 3 + o + 0 3 + + o 0 2 o o o 1 3 o o + 1 3 o + o 1 3 + o o 1 2 - o o 1 2 o - o 1 2 o o - 2 3 + + + 2 3 + + o 2 3 o + + 2 3 + o + 
Mg2CeGa crystallizes in the trigonal R3m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one Ce(1) and three equivalent Ga(1) atoms to form distorted corner-sharing MgCeGa3 tetrahedra. The Mg(1)-Ce(1) bond length is 2.50 Å. All Mg(1)-Ga(1) bond lengths are 3.05 Å. In the second Mg site, Mg(2) is bonded in a linear geometry to one Ce(1) and one Ga(1) atom. The Mg(2)-Ce(1) bond length is 2.50 Å. The Mg(2)-Ga(1) bond length is 2.50 Å. Ce(1) is bonded in a 5-coordinate geometry to one Mg(1), one Mg(2), and three equivalent Ga(1) atoms. All Ce(1)-Ga(1) bond lengths are 3.06 Å. Ga(1) is bonded in a 7-coordinate geometry to one Mg(2), three equivalent Mg(1), and three equivalent Ce(1) atoms.