data_MgNi2Br
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.97
_cell_length_b   4.97
_cell_length_c   4.97
_cell_angle_alpha   134.85
_cell_angle_beta   134.85
_cell_angle_gamma   65.76
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgNi2Br
_chemical_formula_sum   'Mg1 Ni2 Br1'
_cell_volume   60.64
_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
  Mg  Mg1  1  0.0  0.0  0.0  1.0
  Ni  Ni2  1  0.91  0.0  0.09  1.0
  Ni  Ni3  1  0.0  0.91  0.09  1.0
  Br  Br0  1  0.0  0.0  0.17  1.0

data_MgNi2Br
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.39
_cell_length_b   5.39
_cell_length_c   4.97
_cell_angle_alpha   90.0
_cell_angle_beta   122.88
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   MgNi2Br
_chemical_formula_sum   'Mg2 Ni4 Br2'
_cell_volume   121.28
_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
  Mg  Mg0  2  0.0  0.0  0.0  1.0
  Ni  Ni1  4  0.05  0.05  0.18  1.0
  Br  Br2  2  0.0  0.0  0.17  1.0

Mg Ni Ni Br
Mg Ni Ni Br 0 1 - o o 0 2 o - o 0 3 o o o 1 3 + o o 2 3 o + o 
MgNi2Br is Indium-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two MgNi2Br clusters. Mg(1) is bonded in a 3-coordinate geometry to two equivalent Ni(1) and one Br(1) atom. Both Mg(1)-Ni(1) bond lengths are 0.82 Å. The Mg(1)-Br(1) bond length is 0.85 Å. Ni(1) is bonded in a single-bond geometry to one Mg(1) and one Br(1) atom. The Ni(1)-Br(1) bond length is 0.34 Å. Br(1) is bonded in an L-shaped geometry to one Mg(1) and two equivalent Ni(1) atoms.