data_NaMg2Ni
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.83
_cell_length_b   4.83
_cell_length_c   3.2
_cell_angle_alpha   91.02
_cell_angle_beta   91.02
_cell_angle_gamma   91.33
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaMg2Ni
_chemical_formula_sum   'Na1 Mg2 Ni1'
_cell_volume   74.57
_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
  Na  Na2  1  0.0  0.0  0.0  1.0
  Mg  Mg0  1  0.65  0.73  0.6  1.0
  Mg  Mg1  1  0.65  0.27  0.6  1.0
  Ni  Ni3  1  0.38  0.0  0.0  1.0

data_NaMg2Ni
_symmetry_space_group_name_H-M   Pm
_cell_length_a   3.2
_cell_length_b   4.83
_cell_length_c   4.83
_cell_angle_alpha   90.0
_cell_angle_beta   91.02
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   6
_chemical_formula_structural   NaMg2Ni
_chemical_formula_sum   'Na1 Mg2 Ni1'
_cell_volume   74.61
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '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
  Na  Na0  1  0.0  0.0  0.0  1.0
  Mg  Mg1  2  0.6  0.27  0.65  1.0
  Ni  Ni2  1  0.0  0.0  0.38  1.0

Na Mg Mg Ni
NaMg2Ni crystallizes in the monoclinic Pm space group. Na(1) is bonded in a distorted single-bond geometry to four equivalent Mg(1) and one Ni(1) atom. There are two shorter (2.49 Å) and two longer (2.90 Å) Na(1)-Mg(1) bond lengths. The Na(1)-Ni(1) bond length is 1.82 Å. Mg(1) is bonded in a 5-coordinate geometry to two equivalent Na(1), one Mg(1), and two equivalent Ni(1) atoms. The Mg(1)-Mg(1) bond length is 2.20 Å. There is one shorter (2.27 Å) and one longer (2.65 Å) Mg(1)-Ni(1) bond length. Ni(1) is bonded in a 5-coordinate geometry to one Na(1) and four equivalent Mg(1) atoms.