The crystal structure described by Sr(Mg2Ga2)N4 crystallizes in the monoclinic Cm space group. Sr(1) is bonded in a body-centered cubic geometry to two equivalent N(1), two equivalent N(2), two equivalent N(3), and two equivalent N(4) atoms. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form distorted MgN4 trigonal pyramids that share corners with three equivalent Ga(2)N4 tetrahedra, corners with two equivalent Mg(1)N4 trigonal pyramids, corners with three equivalent Mg(2)N4 trigonal pyramids, and edges with two equivalent Ga(1)N4 tetrahedra. In the second Mg site, Mg(2) is bonded to one N(2), one N(3), and two equivalent N(4) atoms to form MgN4 trigonal pyramids that share corners with three equivalent Ga(1)N4 tetrahedra, corners with two equivalent Mg(2)N4 trigonal pyramids, corners with three equivalent Mg(1)N4 trigonal pyramids, and edges with two equivalent Ga(2)N4 tetrahedra. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one N(2), one N(4), and two equivalent N(1) atoms to form GaN4 tetrahedra that share corners with two equivalent Ga(1)N4 tetrahedra, corners with three equivalent Ga(2)N4 tetrahedra, corners with three equivalent Mg(2)N4 trigonal pyramids, and edges with two equivalent Mg(1)N4 trigonal pyramids. In the second Ga site, Ga(2) is bonded to one N(1), one N(4), and two equivalent N(3) atoms to form GaN4 tetrahedra that share corners with two equivalent Ga(2)N4 tetrahedra, corners with three equivalent Ga(1)N4 tetrahedra, corners with three equivalent Mg(1)N4 trigonal pyramids, and edges with two equivalent Mg(2)N4 trigonal pyramids. There are four inequivalent N sites. In the first N site, N(1) is bonded in a 6-coordinate geometry to two equivalent Sr(1), one Mg(1), one Ga(2), and two equivalent Ga(1) atoms. In the second N site, N(2) is bonded to two equivalent Sr(1), one Mg(2), two equivalent Mg(1), and one Ga(1) atom to form distorted edge-sharing NSr2Mg3Ga octahedra. In the third N site, N(3) is bonded in a 6-coordinate geometry to two equivalent Sr(1), one Mg(1), one Mg(2), and two equivalent Ga(2) atoms. In the fourth N site, N(4) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Mg(2), one Ga(1), and one Ga(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrMg2(GaN2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.345
_cell_length_b   6.110
_cell_length_c   6.133
_cell_angle_alpha   94.221
_cell_angle_beta   105.829
_cell_angle_gamma   74.110
_symmetry_Int_Tables_number   1
_cell_volume   115.984
_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
  Sr  Sr0  1  0.997  0.009  0.003  1.0
  Mg  Mg1  1  0.822  0.542  0.187  1.0
  Mg  Mg2  1  0.630  0.195  0.455  1.0
  Ga  Ga3  1  0.192  0.443  0.826  1.0
  Ga  Ga4  1  0.359  0.830  0.548  1.0
  N  N5  1  0.589  0.633  0.812  1.0
  N  N6  1  0.400  0.346  0.146  1.0
  N  N7  1  0.765  0.838  0.367  1.0
  N  N8  1  0.246  0.163  0.656  1.0
[/CIF]
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The crystal structure described by Sr(Mg2Ga2)N4 crystallizes in the monoclinic Cm space group. Sr(1) is bonded in a body-centered cubic geometry to two equivalent N(1), two equivalent N(2), two equivalent N(3), and two equivalent N(4) atoms. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form distorted MgN4 trigonal pyramids that share corners with three equivalent Ga(2)N4 tetrahedra, corners with two equivalent Mg(1)N4 trigonal pyramids, corners with three equivalent Mg(2)N4 trigonal pyramids, and edges with two equivalent Ga(1)N4 tetrahedra. In the second Mg site, Mg(2) is bonded to one N(2), one N(3), and two equivalent N(4) atoms to form MgN4 trigonal pyramids that share corners with three equivalent Ga(1)N4 tetrahedra, corners with two equivalent Mg(2)N4 trigonal pyramids, corners with three equivalent Mg(1)N4 trigonal pyramids, and edges with two equivalent Ga(2)N4 tetrahedra. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded to one N(2), one N(4), and two equivalent N(1) atoms to form GaN4 tetrahedra that share corners with two equivalent Ga(1)N4 tetrahedra, corners with three equivalent Ga(2)N4 tetrahedra, corners with three equivalent Mg(2)N4 trigonal pyramids, and edges with two equivalent Mg(1)N4 trigonal pyramids. In the second Ga site, Ga(2) is bonded to one N(1), one N(4), and two equivalent N(3) atoms to form GaN4 tetrahedra that share corners with two equivalent Ga(2)N4 tetrahedra, corners with three equivalent Ga(1)N4 tetrahedra, corners with three equivalent Mg(1)N4 trigonal pyramids, and edges with two equivalent Mg(2)N4 trigonal pyramids. There are four inequivalent N sites. In the first N site, N(1) is bonded in a 6-coordinate geometry to two equivalent Sr(1), one Mg(1), one Ga(2), and two equivalent Ga(1) atoms. In the second N site, N(2) is bonded to two equivalent Sr(1), one Mg(2), two equivalent Mg(1), and one Ga(1) atom to form distorted edge-sharing NSr2Mg3Ga octahedra. In the third N site, N(3) is bonded in a 6-coordinate geometry to two equivalent Sr(1), one Mg(1), one Mg(2), and two equivalent Ga(2) atoms. In the fourth N site, N(4) is bonded in a 6-coordinate geometry to two equivalent Sr(1), two equivalent Mg(2), one Ga(1), and one Ga(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_SrMg2(GaN2)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.345
_cell_length_b   6.110
_cell_length_c   6.133
_cell_angle_alpha   94.221
_cell_angle_beta   105.829
_cell_angle_gamma   74.110
_symmetry_Int_Tables_number   1
_cell_volume   115.984
_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
  Sr  Sr0  1  0.997  0.009  0.003  1.0
  Mg  Mg1  1  0.822  0.542  0.187  1.0
  Mg  Mg2  1  0.630  0.195  0.455  1.0
  Ga  Ga3  1  0.192  0.443  0.826  1.0
  Ga  Ga4  1  0.359  0.830  0.548  1.0
  N  N5  1  0.589  0.633  0.812  1.0
  N  N6  1  0.400  0.346  0.146  1.0
  N  N7  1  0.765  0.838  0.367  1.0
  N  N8  1  0.246  0.163  0.656  1.0
[/CIF]
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