data_Ca3NiN3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.14
_cell_length_b   7.14
_cell_length_c   5.01
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Ca3NiN3
_chemical_formula_sum   'Ca6 Ni2 N6'
_cell_volume   221.15
_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  0.27  0.95  0.25  1.0
  Ca  Ca1  1  0.85  0.51  0.25  1.0
  Ca  Ca2  1  0.58  0.73  0.25  1.0
  Ca  Ca3  1  0.3  0.23  0.76  1.0
  Ca  Ca4  1  0.72  0.68  0.76  1.0
  Ca  Ca5  1  0.99  0.46  0.76  1.0
  Ni  Ni6  1  0.57  0.06  0.76  1.0
  Ni  Ni7  1  0.0  0.12  0.25  1.0
  N  N8  1  0.3  0.71  0.76  1.0
  N  N9  1  0.64  0.61  0.76  1.0
  N  N10  1  0.78  0.86  0.76  1.0
  N  N11  1  0.27  0.47  0.25  1.0
  N  N12  1  0.93  0.58  0.25  1.0
  N  N13  1  0.79  0.32  0.25  1.0

data_Ca3NiN3
_symmetry_space_group_name_H-M   P2_1/m
_cell_length_a   7.14
_cell_length_b   5.01
_cell_length_c   7.14
_cell_angle_alpha   90.0
_cell_angle_beta   120.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   11
_chemical_formula_structural   Ca3NiN3
_chemical_formula_sum   'Ca6 Ni2 N6'
_cell_volume   221.15
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-x, -y, -z'
  3  '-x, y+1/2, -z'
  4  'x, -y+1/2, 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  2  0.01  0.25  0.14  1.0
  Ca  Ca1  2  0.3  0.75  0.64  1.0
  Ca  Ca2  2  0.43  0.25  0.58  1.0
  Ni  Ni3  2  0.29  0.25  0.97  1.0
  N  N4  2  0.01  0.25  0.62  1.0
  N  N5  2  0.35  0.25  0.52  1.0
  N  N6  2  0.49  0.25  0.77  1.0

Ca Ca Ca Ca Ca Ca Ni Ni N N N N N N
Ca3NiN3 crystallizes in the triclinic P-1 space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 1-coordinate geometry to three equivalent Ni(1) and one N(2) atom. There are a spread of Ca(1)-Ni(1) bond distances ranging from 2.80-3.13 Å. The Ca(1)-N(2) bond length is 2.56 Å. In the second Ca site, Ca(2) is bonded in a distorted bent 120 degrees geometry to one N(2) and one N(3) atom. The Ca(2)-N(2) bond length is 0.54 Å. The Ca(2)-N(3) bond length is 1.19 Å. In the third Ca site, Ca(3) is bonded in a single-bond geometry to one Ni(1) and one N(1) atom. The Ca(3)-Ni(1) bond length is 2.90 Å. The Ca(3)-N(1) bond length is 2.04 Å. Ni(1) is bonded in a 6-coordinate geometry to one Ca(3), three equivalent Ca(1), one N(1), and one N(3) atom. The Ni(1)-N(1) bond length is 2.28 Å. The Ni(1)-N(3) bond length is 2.50 Å. There are three inequivalent N sites. In the first N site, N(1) is bonded in a 2-coordinate geometry to one Ca(3) and one Ni(1) atom. In the second N site, N(2) is bonded in a single-bond geometry to one Ca(1) and one Ca(2) atom. In the third N site, N(3) is bonded in a single-bond geometry to one Ca(2) and one Ni(1) atom.