data_MgNb2Si
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.15
_cell_length_b   5.15
_cell_length_c   5.15
_cell_angle_alpha   137.73
_cell_angle_beta   131.59
_cell_angle_gamma   66.19
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgNb2Si
_chemical_formula_sum   'Mg1 Nb2 Si1'
_cell_volume   67.74
_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  0.39  1.0
  Nb  Nb1  1  0.86  0.0  0.02  1.0
  Nb  Nb2  1  0.0  0.0  0.25  1.0
  Si  Si3  1  0.86  0.0  0.29  1.0

data_MgNb2Si
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.71
_cell_length_b   4.22
_cell_length_c   5.15
_cell_angle_alpha   114.21
_cell_angle_beta   111.13
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgNb2Si
_chemical_formula_sum   'Mg1 Nb2 Si1'
_cell_volume   67.74
_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  0.61  0.61  0.61  1.0
  Nb  Nb1  1  0.75  0.75  0.75  1.0
  Nb  Nb2  1  0.84  0.98  0.84  1.0
  Si  Si3  1  0.56  0.71  0.56  1.0

Mg Nb Nb Si
MgNb2Si is Indium-like structured and crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of one MgNb2Si cluster. Mg(1) is bonded in an L-shaped geometry to one Nb(2) and one Si(1) atom. The Mg(1)-Nb(2) bond length is 0.74 Å. The Mg(1)-Si(1) bond length is 0.55 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a distorted single-bond geometry to one Nb(2) atom. The Nb(1)-Nb(2) bond length is 0.88 Å. In the second Nb site, Nb(2) is bonded in a 3-coordinate geometry to one Mg(1), one Nb(1), and one Si(1) atom. The Nb(2)-Si(1) bond length is 0.91 Å. Si(1) is bonded in a distorted single-bond geometry to one Mg(1) and one Nb(2) atom.