data_MgNi3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.93
_cell_length_b   2.93
_cell_length_c   5.74
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgNi3
_chemical_formula_sum   'Mg1 Ni3'
_cell_volume   49.31
_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  Mg0  1  0.0  0.0  0.0  1.0
  Ni  Ni1  1  0.47  0.47  0.6  1.0
  Ni  Ni2  1  0.0  0.0  0.87  1.0
  Ni  Ni3  1  0.47  0.47  0.14  1.0

data_MgNi3
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.14
_cell_length_b   4.14
_cell_length_c   5.74
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   MgNi3
_chemical_formula_sum   'Mg2 Ni6'
_cell_volume   98.62
_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  2  0.0  0.0  0.87  1.0
  Ni  Ni2  2  0.47  0.0  0.14  1.0
  Ni  Ni3  2  0.47  0.0  0.6  1.0

Mg Ni Ni Ni
Mg Ni Ni Ni 0 2 o o - 0 1 o o - 0 1 o - - 0 1 - o - 0 1 - - - 0 3 o o o 0 3 o - o 0 3 - o o 0 3 - - o 1 2 o o o 1 2 o + o 1 2 + o o 1 2 + + o 1 1 + o o 1 1 o + o 1 3 o o o 1 3 o o + 2 3 o o + 2 3 o - + 2 3 - o + 2 3 - - + 
MgNi3 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a single-bond geometry to one Ni(2) and four equivalent Ni(3) atoms. The Mg(1)-Ni(2) bond length is 0.74 Å. There are a spread of Mg(1)-Ni(3) bond distances ranging from 2.09-2.36 Å. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 9-coordinate geometry to one Ni(3), four equivalent Ni(1), and four equivalent Ni(2) atoms. The Ni(1)-Ni(3) bond length is 2.66 Å. All Ni(1)-Ni(1) bond lengths are 2.93 Å. There are a spread of Ni(1)-Ni(2) bond distances ranging from 2.47-2.70 Å. In the second Ni site, Ni(2) is bonded in a single-bond geometry to one Mg(1) and four equivalent Ni(1) atoms. In the third Ni site, Ni(3) is bonded in a 4-coordinate geometry to four equivalent Mg(1) and one Ni(1) atom.