The structure described by Cr3N4 crystallizes in the trigonal P31c space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one N(2), one N(4), and two equivalent N(1) atoms to form corner-sharing CrN4 tetrahedra. In the second Cr site, Cr(2) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form corner-sharing CrN4 tetrahedra. There are four inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one Cr(2) and two equivalent Cr(1) atoms. In the second N site, N(2) is bonded in a trigonal planar geometry to one Cr(1) and two equivalent Cr(2) atoms. In the third N site, N(3) is bonded in a trigonal planar geometry to three equivalent Cr(2) atoms. In the fourth N site, N(4) is bonded in a trigonal non-coplanar geometry to three equivalent Cr(1) atoms. is represented by the CIF card [CIF]
data_Cr3N4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.176
_cell_length_b   8.176
_cell_length_c   6.030
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   349.099
_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  0.568  0.082  0.793  1.0
  Cr  Cr1  1  0.514  0.432  0.793  1.0
  Cr  Cr2  1  0.918  0.486  0.793  1.0
  Cr  Cr3  1  0.432  0.514  0.293  1.0
  Cr  Cr4  1  0.486  0.918  0.293  1.0
  Cr  Cr5  1  0.082  0.568  0.293  1.0
  Cr  Cr6  1  0.087  0.254  0.023  1.0
  Cr  Cr7  1  0.167  0.913  0.023  1.0
  Cr  Cr8  1  0.746  0.833  0.023  1.0
  Cr  Cr9  1  0.913  0.167  0.523  1.0
  Cr  Cr10  1  0.833  0.746  0.523  1.0
  Cr  Cr11  1  0.254  0.087  0.523  1.0
  N  N12  1  0.045  0.653  0.025  1.0
  N  N13  1  0.608  0.955  0.025  1.0
  N  N14  1  0.347  0.392  0.025  1.0
  N  N15  1  0.955  0.608  0.525  1.0
  N  N16  1  0.392  0.347  0.525  1.0
  N  N17  1  0.653  0.045  0.525  1.0
  N  N18  1  0.002  0.315  0.772  1.0
  N  N19  1  0.313  0.998  0.772  1.0
  N  N20  1  0.685  0.687  0.772  1.0
  N  N21  1  0.998  0.313  0.272  1.0
  N  N22  1  0.687  0.685  0.272  1.0
  N  N23  1  0.315  0.002  0.272  1.0
  N  N24  1  0.000  0.000  0.020  1.0
  N  N25  1  0.000  0.000  0.520  1.0
  N  N26  1  0.333  0.667  0.358  1.0
  N  N27  1  0.667  0.333  0.858  1.0
[/CIF]
.
The structure described by Cr3N4 crystallizes in the trigonal P31c space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one N(2), one N(4), and two equivalent N(1) atoms to form corner-sharing CrN4 tetrahedra. In the second Cr site, Cr(2) is bonded to one N(1), one N(3), and two equivalent N(2) atoms to form corner-sharing CrN4 tetrahedra. There are four inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one Cr(2) and two equivalent Cr(1) atoms. In the second N site, N(2) is bonded in a trigonal planar geometry to one Cr(1) and two equivalent Cr(2) atoms. In the third N site, N(3) is bonded in a trigonal planar geometry to three equivalent Cr(2) atoms. In the fourth N site, N(4) is bonded in a trigonal non-coplanar geometry to three equivalent Cr(1) atoms. is represented by the CIF card [CIF]
data_Cr3N4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.176
_cell_length_b   8.176
_cell_length_c   6.030
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   349.099
_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  0.568  0.082  0.793  1.0
  Cr  Cr1  1  0.514  0.432  0.793  1.0
  Cr  Cr2  1  0.918  0.486  0.793  1.0
  Cr  Cr3  1  0.432  0.514  0.293  1.0
  Cr  Cr4  1  0.486  0.918  0.293  1.0
  Cr  Cr5  1  0.082  0.568  0.293  1.0
  Cr  Cr6  1  0.087  0.254  0.023  1.0
  Cr  Cr7  1  0.167  0.913  0.023  1.0
  Cr  Cr8  1  0.746  0.833  0.023  1.0
  Cr  Cr9  1  0.913  0.167  0.523  1.0
  Cr  Cr10  1  0.833  0.746  0.523  1.0
  Cr  Cr11  1  0.254  0.087  0.523  1.0
  N  N12  1  0.045  0.653  0.025  1.0
  N  N13  1  0.608  0.955  0.025  1.0
  N  N14  1  0.347  0.392  0.025  1.0
  N  N15  1  0.955  0.608  0.525  1.0
  N  N16  1  0.392  0.347  0.525  1.0
  N  N17  1  0.653  0.045  0.525  1.0
  N  N18  1  0.002  0.315  0.772  1.0
  N  N19  1  0.313  0.998  0.772  1.0
  N  N20  1  0.685  0.687  0.772  1.0
  N  N21  1  0.998  0.313  0.272  1.0
  N  N22  1  0.687  0.685  0.272  1.0
  N  N23  1  0.315  0.002  0.272  1.0
  N  N24  1  0.000  0.000  0.020  1.0
  N  N25  1  0.000  0.000  0.520  1.0
  N  N26  1  0.333  0.667  0.358  1.0
  N  N27  1  0.667  0.333  0.858  1.0
[/CIF]
.