data_BaMgNbCu
_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   BaMgNbCu
_chemical_formula_sum   'Ba1 Mg1 Nb1 Cu1'
_cell_volume   93.25
_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
  Ba  Ba0  1  0.4  0.4  0.4  1.0
  Mg  Mg2  1  0.0  0.0  0.0  1.0
  Nb  Nb3  1  0.6  0.6  0.6  1.0
  Cu  Cu1  1  0.8  0.8  0.8  1.0

data_BaMgNbCu
_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   BaMgNbCu
_chemical_formula_sum   'Ba3 Mg3 Nb3 Cu3'
_cell_volume   279.76
_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
  Ba  Ba0  3  0.0  0.0  0.6  1.0
  Mg  Mg1  3  0.0  0.0  0.0  1.0
  Nb  Nb2  3  0.0  0.0  0.4  1.0
  Cu  Cu3  3  0.0  0.0  0.2  1.0

Ba Mg Nb Cu
Ba Mg Nb Cu 0 2 o - o 0 2 - o o 0 2 o o - 0 2 o o o 0 1 o o + 0 1 o + o 0 1 + o o 0 3 - o o 0 3 o - o 0 3 o o - 1 3 - - - 1 3 - - o 1 3 o - - 1 3 - o - 1 2 - - o 1 2 - o - 1 2 o - - 2 3 o o o 
BaMgNbCu crystallizes in the trigonal R3m space group. Ba(1) is bonded in a 10-coordinate geometry to three equivalent Mg(1), four equivalent Nb(1), and three equivalent Cu(1) atoms. All Ba(1)-Mg(1) bond lengths are 3.05 Å. There is one shorter (2.50 Å) and three longer (3.37 Å) Ba(1)-Nb(1) bond lengths. All Ba(1)-Cu(1) bond lengths are 3.06 Å. Mg(1) is bonded in a 1-coordinate geometry to three equivalent Ba(1) and one Cu(1) atom. The Mg(1)-Cu(1) bond length is 2.50 Å. Nb(1) is bonded in a distorted linear geometry to four equivalent Ba(1) and one Cu(1) atom. The Nb(1)-Cu(1) bond length is 2.50 Å. Cu(1) is bonded in a 5-coordinate geometry to three equivalent Ba(1), one Mg(1), and one Nb(1) atom.