The material structure described by Cr3N4 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one N(1), two equivalent N(3), and three equivalent N(2) atoms to form a mixture of edge and corner-sharing CrN6 octahedra. The corner-sharing octahedral tilt angles range from 8-63°. In the second Cr site, Cr(2) is bonded in a 6-coordinate geometry to one N(3), two equivalent N(1), and three equivalent N(4) atoms. In the third Cr site, Cr(3) is bonded to one N(3), one N(4), two equivalent N(1), and two equivalent N(2) atoms to form a mixture of edge and corner-sharing CrN6 octahedra. The corner-sharing octahedral tilt angles range from 8-63°. There are four inequivalent N sites. In the first N site, N(1) is bonded in a 5-coordinate geometry to one Cr(1), two equivalent Cr(2), and two equivalent Cr(3) atoms. In the second N site, N(2) is bonded to two equivalent Cr(3) and three equivalent Cr(1) atoms to form distorted NCr5 square pyramids that share corners with two equivalent N(4)Cr4 tetrahedra, corners with two equivalent N(3)Cr4 trigonal pyramids, edges with four equivalent N(2)Cr5 square pyramids, and edges with three equivalent N(3)Cr4 trigonal pyramids. In the third N site, N(3) is bonded to one Cr(2), one Cr(3), and two equivalent Cr(1) atoms to form NCr4 trigonal pyramids that share corners with two equivalent N(2)Cr5 square pyramids, corners with four equivalent N(4)Cr4 tetrahedra, corners with two equivalent N(3)Cr4 trigonal pyramids, and edges with three equivalent N(2)Cr5 square pyramids. In the fourth N site, N(4) is bonded to one Cr(3) and three equivalent Cr(2) atoms to form distorted NCr4 tetrahedra that share corners with two equivalent N(2)Cr5 square pyramids, corners with two equivalent N(4)Cr4 tetrahedra, corners with four equivalent N(3)Cr4 trigonal pyramids, and edges with two equivalent N(4)Cr4 tetrahedra. is represented by the CIF file [CIF]
data_Cr3N4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.822
_cell_length_b   9.350
_cell_length_c   9.628
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   254.102
_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
  Cr  Cr0  1  0.250  0.919  0.120  1.0
  Cr  Cr1  1  0.250  0.419  0.380  1.0
  Cr  Cr2  1  0.750  0.081  0.880  1.0
  Cr  Cr3  1  0.750  0.581  0.620  1.0
  Cr  Cr4  1  0.250  0.901  0.600  1.0
  Cr  Cr5  1  0.250  0.401  0.900  1.0
  Cr  Cr6  1  0.750  0.099  0.400  1.0
  Cr  Cr7  1  0.750  0.599  0.100  1.0
  Cr  Cr8  1  0.250  0.797  0.860  1.0
  Cr  Cr9  1  0.250  0.297  0.640  1.0
  Cr  Cr10  1  0.750  0.203  0.140  1.0
  Cr  Cr11  1  0.750  0.703  0.360  1.0
  N  N12  1  0.250  0.737  0.207  1.0
  N  N13  1  0.250  0.237  0.293  1.0
  N  N14  1  0.750  0.263  0.793  1.0
  N  N15  1  0.750  0.763  0.707  1.0
  N  N16  1  0.250  0.630  0.480  1.0
  N  N17  1  0.250  0.130  0.020  1.0
  N  N18  1  0.750  0.370  0.520  1.0
  N  N19  1  0.750  0.870  0.980  1.0
  N  N20  1  0.250  0.493  0.727  1.0
  N  N21  1  0.250  0.993  0.773  1.0
  N  N22  1  0.750  0.507  0.273  1.0
  N  N23  1  0.750  0.007  0.227  1.0
  N  N24  1  0.250  0.106  0.534  1.0
  N  N25  1  0.250  0.606  0.966  1.0
  N  N26  1  0.750  0.894  0.466  1.0
  N  N27  1  0.750  0.394  0.034  1.0
[/CIF]
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The material structure described by Cr3N4 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one N(1), two equivalent N(3), and three equivalent N(2) atoms to form a mixture of edge and corner-sharing CrN6 octahedra. The corner-sharing octahedral tilt angles range from 8-63°. In the second Cr site, Cr(2) is bonded in a 6-coordinate geometry to one N(3), two equivalent N(1), and three equivalent N(4) atoms. In the third Cr site, Cr(3) is bonded to one N(3), one N(4), two equivalent N(1), and two equivalent N(2) atoms to form a mixture of edge and corner-sharing CrN6 octahedra. The corner-sharing octahedral tilt angles range from 8-63°. There are four inequivalent N sites. In the first N site, N(1) is bonded in a 5-coordinate geometry to one Cr(1), two equivalent Cr(2), and two equivalent Cr(3) atoms. In the second N site, N(2) is bonded to two equivalent Cr(3) and three equivalent Cr(1) atoms to form distorted NCr5 square pyramids that share corners with two equivalent N(4)Cr4 tetrahedra, corners with two equivalent N(3)Cr4 trigonal pyramids, edges with four equivalent N(2)Cr5 square pyramids, and edges with three equivalent N(3)Cr4 trigonal pyramids. In the third N site, N(3) is bonded to one Cr(2), one Cr(3), and two equivalent Cr(1) atoms to form NCr4 trigonal pyramids that share corners with two equivalent N(2)Cr5 square pyramids, corners with four equivalent N(4)Cr4 tetrahedra, corners with two equivalent N(3)Cr4 trigonal pyramids, and edges with three equivalent N(2)Cr5 square pyramids. In the fourth N site, N(4) is bonded to one Cr(3) and three equivalent Cr(2) atoms to form distorted NCr4 tetrahedra that share corners with two equivalent N(2)Cr5 square pyramids, corners with two equivalent N(4)Cr4 tetrahedra, corners with four equivalent N(3)Cr4 trigonal pyramids, and edges with two equivalent N(4)Cr4 tetrahedra. is represented by the CIF file [CIF]
data_Cr3N4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.822
_cell_length_b   9.350
_cell_length_c   9.628
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   254.102
_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
  Cr  Cr0  1  0.250  0.919  0.120  1.0
  Cr  Cr1  1  0.250  0.419  0.380  1.0
  Cr  Cr2  1  0.750  0.081  0.880  1.0
  Cr  Cr3  1  0.750  0.581  0.620  1.0
  Cr  Cr4  1  0.250  0.901  0.600  1.0
  Cr  Cr5  1  0.250  0.401  0.900  1.0
  Cr  Cr6  1  0.750  0.099  0.400  1.0
  Cr  Cr7  1  0.750  0.599  0.100  1.0
  Cr  Cr8  1  0.250  0.797  0.860  1.0
  Cr  Cr9  1  0.250  0.297  0.640  1.0
  Cr  Cr10  1  0.750  0.203  0.140  1.0
  Cr  Cr11  1  0.750  0.703  0.360  1.0
  N  N12  1  0.250  0.737  0.207  1.0
  N  N13  1  0.250  0.237  0.293  1.0
  N  N14  1  0.750  0.263  0.793  1.0
  N  N15  1  0.750  0.763  0.707  1.0
  N  N16  1  0.250  0.630  0.480  1.0
  N  N17  1  0.250  0.130  0.020  1.0
  N  N18  1  0.750  0.370  0.520  1.0
  N  N19  1  0.750  0.870  0.980  1.0
  N  N20  1  0.250  0.493  0.727  1.0
  N  N21  1  0.250  0.993  0.773  1.0
  N  N22  1  0.750  0.507  0.273  1.0
  N  N23  1  0.750  0.007  0.227  1.0
  N  N24  1  0.250  0.106  0.534  1.0
  N  N25  1  0.250  0.606  0.966  1.0
  N  N26  1  0.750  0.894  0.466  1.0
  N  N27  1  0.750  0.394  0.034  1.0
[/CIF]
.