The material structure described by Mg2MnAs2 crystallizes in the trigonal P3m1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to three equivalent As(1) and three equivalent As(2) atoms to form MgAs6 octahedra that share corners with six equivalent Mg(2)As4 tetrahedra, corners with six equivalent Mn(1)As4 tetrahedra, edges with six equivalent Mg(1)As6 octahedra, edges with three equivalent Mg(2)As4 tetrahedra, and edges with three equivalent Mn(1)As4 tetrahedra. In the second Mg site, Mg(2) is bonded to one As(1) and three equivalent As(2) atoms to form distorted MgAs4 tetrahedra that share corners with six equivalent Mg(1)As6 octahedra, corners with six equivalent Mg(2)As4 tetrahedra, edges with three equivalent Mg(1)As6 octahedra, and edges with three equivalent Mn(1)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-57°. Mn(1) is bonded to one As(2) and three equivalent As(1) atoms to form distorted MnAs4 tetrahedra that share corners with six equivalent Mg(1)As6 octahedra, corners with six equivalent Mn(1)As4 tetrahedra, edges with three equivalent Mg(1)As6 octahedra, and edges with three equivalent Mg(2)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-57°. There are two inequivalent As sites. In the first As site, As(1) is bonded to one Mg(2), three equivalent Mg(1), and three equivalent Mn(1) atoms to form distorted AsMg4Mn3 pentagonal bipyramids that share corners with three equivalent As(2)Mg6Mn pentagonal bipyramids, edges with six equivalent As(1)Mg4Mn3 pentagonal bipyramids, and edges with six equivalent As(2)Mg6Mn pentagonal bipyramids. In the second As site, As(2) is bonded to three equivalent Mg(1), three equivalent Mg(2), and one Mn(1) atom to form distorted AsMg6Mn pentagonal bipyramids that share corners with three equivalent As(1)Mg4Mn3 pentagonal bipyramids, edges with six equivalent As(1)Mg4Mn3 pentagonal bipyramids, and edges with six equivalent As(2)Mg6Mn pentagonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2MnAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.231
_cell_length_b   4.231
_cell_length_c   6.730
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   104.329
_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  0.000  0.000  0.999  1.0
  Mg  Mg1  1  0.667  0.333  0.365  1.0
  Mn  Mn2  1  0.333  0.667  0.635  1.0
  As  As3  1  0.667  0.333  0.766  1.0
  As  As4  1  0.333  0.667  0.234  1.0
[/CIF]
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The material structure described by Mg2MnAs2 crystallizes in the trigonal P3m1 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to three equivalent As(1) and three equivalent As(2) atoms to form MgAs6 octahedra that share corners with six equivalent Mg(2)As4 tetrahedra, corners with six equivalent Mn(1)As4 tetrahedra, edges with six equivalent Mg(1)As6 octahedra, edges with three equivalent Mg(2)As4 tetrahedra, and edges with three equivalent Mn(1)As4 tetrahedra. In the second Mg site, Mg(2) is bonded to one As(1) and three equivalent As(2) atoms to form distorted MgAs4 tetrahedra that share corners with six equivalent Mg(1)As6 octahedra, corners with six equivalent Mg(2)As4 tetrahedra, edges with three equivalent Mg(1)As6 octahedra, and edges with three equivalent Mn(1)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-57°. Mn(1) is bonded to one As(2) and three equivalent As(1) atoms to form distorted MnAs4 tetrahedra that share corners with six equivalent Mg(1)As6 octahedra, corners with six equivalent Mn(1)As4 tetrahedra, edges with three equivalent Mg(1)As6 octahedra, and edges with three equivalent Mg(2)As4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-57°. There are two inequivalent As sites. In the first As site, As(1) is bonded to one Mg(2), three equivalent Mg(1), and three equivalent Mn(1) atoms to form distorted AsMg4Mn3 pentagonal bipyramids that share corners with three equivalent As(2)Mg6Mn pentagonal bipyramids, edges with six equivalent As(1)Mg4Mn3 pentagonal bipyramids, and edges with six equivalent As(2)Mg6Mn pentagonal bipyramids. In the second As site, As(2) is bonded to three equivalent Mg(1), three equivalent Mg(2), and one Mn(1) atom to form distorted AsMg6Mn pentagonal bipyramids that share corners with three equivalent As(1)Mg4Mn3 pentagonal bipyramids, edges with six equivalent As(1)Mg4Mn3 pentagonal bipyramids, and edges with six equivalent As(2)Mg6Mn pentagonal bipyramids. is represented by the Crystallographic Information File (CIF) [CIF]
data_Mg2MnAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.231
_cell_length_b   4.231
_cell_length_c   6.730
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   104.329
_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  0.000  0.000  0.999  1.0
  Mg  Mg1  1  0.667  0.333  0.365  1.0
  Mn  Mn2  1  0.333  0.667  0.635  1.0
  As  As3  1  0.667  0.333  0.766  1.0
  As  As4  1  0.333  0.667  0.234  1.0
[/CIF]
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