data_MgBi2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.29
_cell_length_b   8.29
_cell_length_c   8.29
_cell_angle_alpha   28.36
_cell_angle_beta   28.36
_cell_angle_gamma   28.36
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MgBi2As
_chemical_formula_sum   'Mg1 Bi2 As1'
_cell_volume   113.63
_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  Mg3  1  0.0  0.0  0.0  1.0
  Bi  Bi1  1  0.0  0.0  0.04  1.0
  Bi  Bi2  1  0.0  0.0  0.82  1.0
  As  As0  1  0.0  0.0  0.93  1.0

data_MgBi2As
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.04
_cell_length_b   4.06
_cell_length_c   8.29
_cell_angle_alpha   90.0
_cell_angle_beta   106.43
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   MgBi2As
_chemical_formula_sum   'Mg2 Bi4 As2'
_cell_volume   227.27
_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
  Bi  Bi1  2  -0.0  0.0  0.18  1.0
  Bi  Bi2  2  0.0  0.0  0.96  1.0
  As  As3  2  -0.0  0.0  0.07  1.0

Mg Bi Bi As
Mg Bi Bi As 0 1 o o o 0 3 o o - 2 3 o o o 
MgBi2As is Cyanogen Chloride-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two MgBi2As clusters. Mg(1) is bonded in a linear geometry to one Bi(1) and one As(1) atom. The Mg(1)-Bi(1) bond length is 0.32 Å. The Mg(1)-As(1) bond length is 0.61 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a single-bond geometry to one Mg(1) atom. In the second Bi site, Bi(2) is bonded in a single-bond geometry to one As(1) atom. The Bi(2)-As(1) bond length is 0.92 Å. As(1) is bonded in a linear geometry to one Mg(1) and one Bi(2) atom.