The material structure described by Ca7Mg2N6 crystallizes in the monoclinic C2/m space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent N(2) and four equivalent N(1) atoms to form CaN6 octahedra that share corners with four equivalent Mg(1)N4 tetrahedra, corners with eight equivalent Ca(3)N4 tetrahedra, edges with two equivalent Mg(1)N4 tetrahedra, and edges with four equivalent Ca(3)N4 tetrahedra. In the second Ca site, Ca(2) is bonded in a see-saw-like geometry to two equivalent N(1) and two equivalent N(2) atoms. In the third Ca site, Ca(3) is bonded to one N(2) and three equivalent N(1) atoms to form distorted CaN4 tetrahedra that share corners with two equivalent Ca(1)N6 octahedra, corners with three equivalent Ca(3)N4 tetrahedra, corners with three equivalent Mg(1)N4 tetrahedra,  an edgeedge with one Ca(1)N6 octahedra,  an edgeedge with one Mg(1)N4 tetrahedra, and edges with two equivalent Ca(3)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-65°. Mg(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form MgN4 tetrahedra that share corners with two equivalent Ca(1)N6 octahedra, corners with six equivalent Ca(3)N4 tetrahedra,  an edgeedge with one Ca(1)N6 octahedra,  an edgeedge with one Mg(1)N4 tetrahedra, and edges with two equivalent Ca(3)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 17-60°. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(2), three equivalent Ca(3), and one Mg(1) atom. In the second N site, N(2) is bonded to one Ca(1), two equivalent Ca(2), two equivalent Ca(3), and two equivalent Mg(1) atoms to form a mixture of distorted corner and edge-sharing NCa5Mg2 pentagonal bipyramids. is represented by the CIF file [CIF]
data_Ca7Mg2N6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.036
_cell_length_b   12.660
_cell_length_c   6.423
_cell_angle_alpha   90.000
_cell_angle_beta   88.004
_cell_angle_gamma   25.881
_symmetry_Int_Tables_number   1
_cell_volume   248.955
_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
  Ca  Ca0  1  0.000  0.500  0.000  1.0
  Ca  Ca1  1  0.000  0.378  0.500  1.0
  Ca  Ca2  1  0.000  0.622  0.500  1.0
  Ca  Ca3  1  0.700  0.978  0.825  1.0
  Ca  Ca4  1  0.700  0.323  0.825  1.0
  Ca  Ca5  1  0.300  0.022  0.175  1.0
  Ca  Ca6  1  0.300  0.677  0.175  1.0
  Mg  Mg7  1  0.242  0.879  0.673  1.0
  Mg  Mg8  1  0.758  0.121  0.327  1.0
  N  N9  1  0.480  0.905  0.804  1.0
  N  N10  1  0.480  0.615  0.804  1.0
  N  N11  1  0.520  0.095  0.196  1.0
  N  N12  1  0.520  0.385  0.196  1.0
  N  N13  1  0.489  0.755  0.341  1.0
  N  N14  1  0.511  0.245  0.659  1.0
[/CIF]
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The material structure described by Ca7Mg2N6 crystallizes in the monoclinic C2/m space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent N(2) and four equivalent N(1) atoms to form CaN6 octahedra that share corners with four equivalent Mg(1)N4 tetrahedra, corners with eight equivalent Ca(3)N4 tetrahedra, edges with two equivalent Mg(1)N4 tetrahedra, and edges with four equivalent Ca(3)N4 tetrahedra. In the second Ca site, Ca(2) is bonded in a see-saw-like geometry to two equivalent N(1) and two equivalent N(2) atoms. In the third Ca site, Ca(3) is bonded to one N(2) and three equivalent N(1) atoms to form distorted CaN4 tetrahedra that share corners with two equivalent Ca(1)N6 octahedra, corners with three equivalent Ca(3)N4 tetrahedra, corners with three equivalent Mg(1)N4 tetrahedra,  an edgeedge with one Ca(1)N6 octahedra,  an edgeedge with one Mg(1)N4 tetrahedra, and edges with two equivalent Ca(3)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-65°. Mg(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form MgN4 tetrahedra that share corners with two equivalent Ca(1)N6 octahedra, corners with six equivalent Ca(3)N4 tetrahedra,  an edgeedge with one Ca(1)N6 octahedra,  an edgeedge with one Mg(1)N4 tetrahedra, and edges with two equivalent Ca(3)N4 tetrahedra. The corner-sharing octahedral tilt angles range from 17-60°. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 6-coordinate geometry to one Ca(1), one Ca(2), three equivalent Ca(3), and one Mg(1) atom. In the second N site, N(2) is bonded to one Ca(1), two equivalent Ca(2), two equivalent Ca(3), and two equivalent Mg(1) atoms to form a mixture of distorted corner and edge-sharing NCa5Mg2 pentagonal bipyramids. is represented by the CIF file [CIF]
data_Ca7Mg2N6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.036
_cell_length_b   12.660
_cell_length_c   6.423
_cell_angle_alpha   90.000
_cell_angle_beta   88.004
_cell_angle_gamma   25.881
_symmetry_Int_Tables_number   1
_cell_volume   248.955
_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
  Ca  Ca0  1  0.000  0.500  0.000  1.0
  Ca  Ca1  1  0.000  0.378  0.500  1.0
  Ca  Ca2  1  0.000  0.622  0.500  1.0
  Ca  Ca3  1  0.700  0.978  0.825  1.0
  Ca  Ca4  1  0.700  0.323  0.825  1.0
  Ca  Ca5  1  0.300  0.022  0.175  1.0
  Ca  Ca6  1  0.300  0.677  0.175  1.0
  Mg  Mg7  1  0.242  0.879  0.673  1.0
  Mg  Mg8  1  0.758  0.121  0.327  1.0
  N  N9  1  0.480  0.905  0.804  1.0
  N  N10  1  0.480  0.615  0.804  1.0
  N  N11  1  0.520  0.095  0.196  1.0
  N  N12  1  0.520  0.385  0.196  1.0
  N  N13  1  0.489  0.755  0.341  1.0
  N  N14  1  0.511  0.245  0.659  1.0
[/CIF]
.