The compound described by Ca5MgN4 is Ilmenite-like structured and crystallizes in the orthorhombic Pmmn space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted CaN4 trigonal pyramids that share corners with two equivalent Ca(2)N4 tetrahedra, corners with two equivalent Mg(1)N4 tetrahedra, corners with eight equivalent Ca(1)N4 trigonal pyramids,  an edgeedge with one Ca(2)N4 tetrahedra,  an edgeedge with one Mg(1)N4 tetrahedra, and edges with two equivalent Ca(1)N4 trigonal pyramids. In the second Ca site, Ca(2) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form CaN4 tetrahedra that share corners with four equivalent Mg(1)N4 tetrahedra, corners with eight equivalent Ca(1)N4 trigonal pyramids, and edges with four equivalent Ca(1)N4 trigonal pyramids. Mg(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form MgN4 tetrahedra that share corners with four equivalent Ca(2)N4 tetrahedra, corners with eight equivalent Ca(1)N4 trigonal pyramids, and edges with four equivalent Ca(1)N4 trigonal pyramids. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 6-coordinate geometry to one Ca(2), four equivalent Ca(1), and one Mg(1) atom. In the second N site, N(2) is bonded to one Ca(2), four equivalent Ca(1), and one Mg(1) atom to form a mixture of distorted corner and edge-sharing NCa5Mg octahedra. The corner-sharing octahedral tilt angles range from 63-65°. is represented by the CIF card [CIF]
data_Ca5MgN4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.937
_cell_length_b   7.590
_cell_length_c   5.866
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   353.367
_cell_formula_units_Z   2
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  0.551  0.502  0.245  1.0
  Ca  Ca1  1  0.949  0.502  0.245  1.0
  Ca  Ca2  1  0.551  0.998  0.245  1.0
  Ca  Ca3  1  0.949  0.998  0.245  1.0
  Ca  Ca4  1  0.449  0.498  0.755  1.0
  Ca  Ca5  1  0.051  0.498  0.755  1.0
  Ca  Ca6  1  0.449  0.002  0.755  1.0
  Ca  Ca7  1  0.051  0.002  0.755  1.0
  Ca  Ca8  1  0.750  0.750  0.703  1.0
  Ca  Ca9  1  0.250  0.250  0.297  1.0
  Mg  Mg10  1  0.750  0.250  0.719  1.0
  Mg  Mg11  1  0.250  0.750  0.281  1.0
  N  N12  1  0.750  0.009  0.923  1.0
  N  N13  1  0.750  0.491  0.923  1.0
  N  N14  1  0.250  0.991  0.077  1.0
  N  N15  1  0.250  0.509  0.077  1.0
  N  N16  1  0.491  0.750  0.488  1.0
  N  N17  1  0.009  0.750  0.488  1.0
  N  N18  1  0.509  0.250  0.512  1.0
  N  N19  1  0.991  0.250  0.512  1.0
[/CIF]
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The compound described by Ca5MgN4 is Ilmenite-like structured and crystallizes in the orthorhombic Pmmn space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form distorted CaN4 trigonal pyramids that share corners with two equivalent Ca(2)N4 tetrahedra, corners with two equivalent Mg(1)N4 tetrahedra, corners with eight equivalent Ca(1)N4 trigonal pyramids,  an edgeedge with one Ca(2)N4 tetrahedra,  an edgeedge with one Mg(1)N4 tetrahedra, and edges with two equivalent Ca(1)N4 trigonal pyramids. In the second Ca site, Ca(2) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form CaN4 tetrahedra that share corners with four equivalent Mg(1)N4 tetrahedra, corners with eight equivalent Ca(1)N4 trigonal pyramids, and edges with four equivalent Ca(1)N4 trigonal pyramids. Mg(1) is bonded to two equivalent N(1) and two equivalent N(2) atoms to form MgN4 tetrahedra that share corners with four equivalent Ca(2)N4 tetrahedra, corners with eight equivalent Ca(1)N4 trigonal pyramids, and edges with four equivalent Ca(1)N4 trigonal pyramids. There are two inequivalent N sites. In the first N site, N(1) is bonded in a 6-coordinate geometry to one Ca(2), four equivalent Ca(1), and one Mg(1) atom. In the second N site, N(2) is bonded to one Ca(2), four equivalent Ca(1), and one Mg(1) atom to form a mixture of distorted corner and edge-sharing NCa5Mg octahedra. The corner-sharing octahedral tilt angles range from 63-65°. is represented by the CIF card [CIF]
data_Ca5MgN4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.937
_cell_length_b   7.590
_cell_length_c   5.866
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   353.367
_cell_formula_units_Z   2
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  0.551  0.502  0.245  1.0
  Ca  Ca1  1  0.949  0.502  0.245  1.0
  Ca  Ca2  1  0.551  0.998  0.245  1.0
  Ca  Ca3  1  0.949  0.998  0.245  1.0
  Ca  Ca4  1  0.449  0.498  0.755  1.0
  Ca  Ca5  1  0.051  0.498  0.755  1.0
  Ca  Ca6  1  0.449  0.002  0.755  1.0
  Ca  Ca7  1  0.051  0.002  0.755  1.0
  Ca  Ca8  1  0.750  0.750  0.703  1.0
  Ca  Ca9  1  0.250  0.250  0.297  1.0
  Mg  Mg10  1  0.750  0.250  0.719  1.0
  Mg  Mg11  1  0.250  0.750  0.281  1.0
  N  N12  1  0.750  0.009  0.923  1.0
  N  N13  1  0.750  0.491  0.923  1.0
  N  N14  1  0.250  0.991  0.077  1.0
  N  N15  1  0.250  0.509  0.077  1.0
  N  N16  1  0.491  0.750  0.488  1.0
  N  N17  1  0.009  0.750  0.488  1.0
  N  N18  1  0.509  0.250  0.512  1.0
  N  N19  1  0.991  0.250  0.512  1.0
[/CIF]
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