data_Cu3N
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.03
_cell_length_b   6.03
_cell_length_c   2.83
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cu3N
_chemical_formula_sum   'Cu6 N2'
_cell_volume   88.96
_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
  Cu  Cu0  1  0.29  0.22  0.12  1.0
  Cu  Cu1  1  0.0  0.99  0.12  1.0
  Cu  Cu2  1  0.71  0.22  0.12  1.0
  Cu  Cu3  1  0.3  1.0  0.71  1.0
  Cu  Cu4  1  0.73  1.0  0.71  1.0
  Cu  Cu5  1  0.01  0.23  0.71  1.0
  N  N6  1  0.01  0.74  0.12  1.0
  N  N7  1  0.0  0.48  0.71  1.0

data_Cu3N
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.83
_cell_length_b   6.03
_cell_length_c   6.03
_cell_angle_alpha   120.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Cu3N
_chemical_formula_sum   'Cu6 N2'
_cell_volume   88.96
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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
  Cu  Cu0  2  0.29  0.01  0.12  1.0
  Cu  Cu1  2  0.29  0.29  0.89  1.0
  Cu  Cu2  2  0.29  0.72  0.89  1.0
  N  N3  2  0.29  0.99  0.37  1.0

Cu Cu Cu Cu Cu Cu N N
Cu3N is black P-like structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two Cu3N clusters. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 2-coordinate geometry to one Cu(2) and one Cu(3) atom. The Cu(1)-Cu(2) bond length is 1.59 Å. The Cu(1)-Cu(3) bond length is 1.83 Å. In the second Cu site, Cu(2) is bonded in a distorted single-bond geometry to one Cu(1) and one N(1) atom. The Cu(2)-N(1) bond length is 1.57 Å. In the third Cu site, Cu(3) is bonded in a 1-coordinate geometry to one Cu(1) and one N(1) atom. The Cu(3)-N(1) bond length is 2.02 Å. N(1) is bonded in a 1-coordinate geometry to one Cu(2) and one Cu(3) atom.