The structure described by Mg4CN4 crystallizes in the orthorhombic Pnma space group. There are four 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 Mg(2)N6 octahedra, corners with three equivalent Mg(3)N5 square pyramids, corners with two equivalent Mg(1)N4 trigonal pyramids, and edges with three equivalent Mg(2)N6 octahedra. The corner-sharing octahedral tilt angles range from 1-5°. In the second Mg site, Mg(2) is bonded to one N(1), two equivalent N(3), and three equivalent N(2) atoms to form MgN6 octahedra that share corners with three equivalent Mg(1)N4 trigonal pyramids, edges with four equivalent Mg(2)N6 octahedra, edges with two equivalent Mg(3)N5 square pyramids, and edges with three equivalent Mg(1)N4 trigonal pyramids. In the third Mg site, Mg(3) is bonded to one N(3), two equivalent N(1), and two equivalent N(4) atoms to form distorted MgN5 square pyramids that share corners with three equivalent Mg(1)N4 trigonal pyramids, edges with two equivalent Mg(2)N6 octahedra, and edges with two equivalent Mg(3)N5 square pyramids. In the fourth Mg site, Mg(4) is bonded in a 5-coordinate geometry to one N(2), two equivalent N(1), and two equivalent N(4) atoms. C(1) is bonded in a linear geometry to one N(3) and one N(4) atom. There are four inequivalent N sites. In the first N site, N(4) is bonded in a 5-coordinate geometry to two equivalent Mg(3), two equivalent Mg(4), and one C(1) atom. In the second N site, N(1) is bonded to one Mg(1), one Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms to form a mixture of edge and corner-sharing NMg6 octahedra. The corner-sharing octahedral tilt angles range from 13-56°. In the third N site, N(2) is bonded to one Mg(4), two equivalent Mg(1), and three equivalent Mg(2) atoms to form a mixture of edge and corner-sharing NMg6 octahedra. The corner-sharing octahedral tilt angles range from 13-56°. In the fourth N site, N(3) is bonded in a 5-coordinate geometry to one Mg(1), one Mg(3), two equivalent Mg(2), and one C(1) atom. is represented by the CIF file [CIF]
data_Mg4CN4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.228
_cell_length_b   3.202
_cell_length_c   12.590
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   412.315
_cell_formula_units_Z   4
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  0.136  0.250  0.160  1.0
  Mg  Mg1  1  0.636  0.250  0.340  1.0
  Mg  Mg2  1  0.864  0.750  0.840  1.0
  Mg  Mg3  1  0.364  0.750  0.660  1.0
  Mg  Mg4  1  0.894  0.250  0.049  1.0
  Mg  Mg5  1  0.394  0.250  0.451  1.0
  Mg  Mg6  1  0.106  0.750  0.951  1.0
  Mg  Mg7  1  0.606  0.750  0.549  1.0
  Mg  Mg8  1  0.355  0.250  0.863  1.0
  Mg  Mg9  1  0.855  0.250  0.637  1.0
  Mg  Mg10  1  0.645  0.750  0.137  1.0
  Mg  Mg11  1  0.145  0.750  0.363  1.0
  Mg  Mg12  1  0.117  0.250  0.763  1.0
  Mg  Mg13  1  0.617  0.250  0.737  1.0
  Mg  Mg14  1  0.883  0.750  0.237  1.0
  Mg  Mg15  1  0.383  0.750  0.263  1.0
  C  C16  1  0.382  0.250  0.075  1.0
  C  C17  1  0.882  0.250  0.425  1.0
  C  C18  1  0.618  0.750  0.925  1.0
  C  C19  1  0.118  0.750  0.575  1.0
  N  N20  1  0.756  0.250  0.202  1.0
  N  N21  1  0.256  0.250  0.298  1.0
  N  N22  1  0.244  0.750  0.798  1.0
  N  N23  1  0.744  0.750  0.702  1.0
  N  N24  1  0.981  0.250  0.888  1.0
  N  N25  1  0.481  0.250  0.612  1.0
  N  N26  1  0.019  0.750  0.112  1.0
  N  N27  1  0.519  0.750  0.388  1.0
  N  N28  1  0.279  0.250  0.023  1.0
  N  N29  1  0.779  0.250  0.477  1.0
  N  N30  1  0.721  0.750  0.977  1.0
  N  N31  1  0.221  0.750  0.523  1.0
  N  N32  1  0.482  0.250  0.131  1.0
  N  N33  1  0.982  0.250  0.369  1.0
  N  N34  1  0.518  0.750  0.869  1.0
  N  N35  1  0.018  0.750  0.631  1.0
[/CIF]
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The structure described by Mg4CN4 crystallizes in the orthorhombic Pnma space group. There are four 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 Mg(2)N6 octahedra, corners with three equivalent Mg(3)N5 square pyramids, corners with two equivalent Mg(1)N4 trigonal pyramids, and edges with three equivalent Mg(2)N6 octahedra. The corner-sharing octahedral tilt angles range from 1-5°. In the second Mg site, Mg(2) is bonded to one N(1), two equivalent N(3), and three equivalent N(2) atoms to form MgN6 octahedra that share corners with three equivalent Mg(1)N4 trigonal pyramids, edges with four equivalent Mg(2)N6 octahedra, edges with two equivalent Mg(3)N5 square pyramids, and edges with three equivalent Mg(1)N4 trigonal pyramids. In the third Mg site, Mg(3) is bonded to one N(3), two equivalent N(1), and two equivalent N(4) atoms to form distorted MgN5 square pyramids that share corners with three equivalent Mg(1)N4 trigonal pyramids, edges with two equivalent Mg(2)N6 octahedra, and edges with two equivalent Mg(3)N5 square pyramids. In the fourth Mg site, Mg(4) is bonded in a 5-coordinate geometry to one N(2), two equivalent N(1), and two equivalent N(4) atoms. C(1) is bonded in a linear geometry to one N(3) and one N(4) atom. There are four inequivalent N sites. In the first N site, N(4) is bonded in a 5-coordinate geometry to two equivalent Mg(3), two equivalent Mg(4), and one C(1) atom. In the second N site, N(1) is bonded to one Mg(1), one Mg(2), two equivalent Mg(3), and two equivalent Mg(4) atoms to form a mixture of edge and corner-sharing NMg6 octahedra. The corner-sharing octahedral tilt angles range from 13-56°. In the third N site, N(2) is bonded to one Mg(4), two equivalent Mg(1), and three equivalent Mg(2) atoms to form a mixture of edge and corner-sharing NMg6 octahedra. The corner-sharing octahedral tilt angles range from 13-56°. In the fourth N site, N(3) is bonded in a 5-coordinate geometry to one Mg(1), one Mg(3), two equivalent Mg(2), and one C(1) atom. is represented by the CIF file [CIF]
data_Mg4CN4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.228
_cell_length_b   3.202
_cell_length_c   12.590
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   412.315
_cell_formula_units_Z   4
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  0.136  0.250  0.160  1.0
  Mg  Mg1  1  0.636  0.250  0.340  1.0
  Mg  Mg2  1  0.864  0.750  0.840  1.0
  Mg  Mg3  1  0.364  0.750  0.660  1.0
  Mg  Mg4  1  0.894  0.250  0.049  1.0
  Mg  Mg5  1  0.394  0.250  0.451  1.0
  Mg  Mg6  1  0.106  0.750  0.951  1.0
  Mg  Mg7  1  0.606  0.750  0.549  1.0
  Mg  Mg8  1  0.355  0.250  0.863  1.0
  Mg  Mg9  1  0.855  0.250  0.637  1.0
  Mg  Mg10  1  0.645  0.750  0.137  1.0
  Mg  Mg11  1  0.145  0.750  0.363  1.0
  Mg  Mg12  1  0.117  0.250  0.763  1.0
  Mg  Mg13  1  0.617  0.250  0.737  1.0
  Mg  Mg14  1  0.883  0.750  0.237  1.0
  Mg  Mg15  1  0.383  0.750  0.263  1.0
  C  C16  1  0.382  0.250  0.075  1.0
  C  C17  1  0.882  0.250  0.425  1.0
  C  C18  1  0.618  0.750  0.925  1.0
  C  C19  1  0.118  0.750  0.575  1.0
  N  N20  1  0.756  0.250  0.202  1.0
  N  N21  1  0.256  0.250  0.298  1.0
  N  N22  1  0.244  0.750  0.798  1.0
  N  N23  1  0.744  0.750  0.702  1.0
  N  N24  1  0.981  0.250  0.888  1.0
  N  N25  1  0.481  0.250  0.612  1.0
  N  N26  1  0.019  0.750  0.112  1.0
  N  N27  1  0.519  0.750  0.388  1.0
  N  N28  1  0.279  0.250  0.023  1.0
  N  N29  1  0.779  0.250  0.477  1.0
  N  N30  1  0.721  0.750  0.977  1.0
  N  N31  1  0.221  0.750  0.523  1.0
  N  N32  1  0.482  0.250  0.131  1.0
  N  N33  1  0.982  0.250  0.369  1.0
  N  N34  1  0.518  0.750  0.869  1.0
  N  N35  1  0.018  0.750  0.631  1.0
[/CIF]
.