The material described by Mg3As2 crystallizes in the trigonal P-3m1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to four equivalent As(1) atoms to form MgAs4 tetrahedra that share corners with six equivalent Mg(2)As6 octahedra, corners with six equivalent Mg(1)As4 tetrahedra, edges with three equivalent Mg(2)As6 octahedra, and edges with three equivalent Mg(1)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 14-57°. In the second Mg site, Mg(2) is bonded to six equivalent As(1) atoms to form MgAs6 octahedra that share corners with twelve equivalent Mg(1)As4 tetrahedra, edges with six equivalent Mg(2)As6 octahedra, and edges with six equivalent Mg(1)As4 tetrahedra. As(1) is bonded to three equivalent Mg(2) and four equivalent Mg(1) atoms to form a mixture of distorted corner and edge-sharing AsMg7 pentagonal bipyramids. is represented by the CIF card [CIF]
data_Mg3As2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.261
_cell_length_b   4.261
_cell_length_c   6.738
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   105.951
_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  0.667  0.333  0.357  1.0
  Mg  Mg1  1  0.333  0.667  0.643  1.0
  Mg  Mg2  1  0.000  0.000  0.000  1.0
  As  As3  1  0.667  0.333  0.767  1.0
  As  As4  1  0.333  0.667  0.233  1.0
[/CIF]
.
The material described by Mg3As2 crystallizes in the trigonal P-3m1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to four equivalent As(1) atoms to form MgAs4 tetrahedra that share corners with six equivalent Mg(2)As6 octahedra, corners with six equivalent Mg(1)As4 tetrahedra, edges with three equivalent Mg(2)As6 octahedra, and edges with three equivalent Mg(1)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 14-57°. In the second Mg site, Mg(2) is bonded to six equivalent As(1) atoms to form MgAs6 octahedra that share corners with twelve equivalent Mg(1)As4 tetrahedra, edges with six equivalent Mg(2)As6 octahedra, and edges with six equivalent Mg(1)As4 tetrahedra. As(1) is bonded to three equivalent Mg(2) and four equivalent Mg(1) atoms to form a mixture of distorted corner and edge-sharing AsMg7 pentagonal bipyramids. is represented by the CIF card [CIF]
data_Mg3As2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.261
_cell_length_b   4.261
_cell_length_c   6.738
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   105.951
_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  0.667  0.333  0.357  1.0
  Mg  Mg1  1  0.333  0.667  0.643  1.0
  Mg  Mg2  1  0.000  0.000  0.000  1.0
  As  As3  1  0.667  0.333  0.767  1.0
  As  As4  1  0.333  0.667  0.233  1.0
[/CIF]
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