data_Fe(NiAs)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.96
_cell_length_b   6.96
_cell_length_c   6.96
_cell_angle_alpha   120.17
_cell_angle_beta   82.75
_cell_angle_gamma   128.59
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Fe(NiAs)2
_chemical_formula_sum   'Fe3 Ni6 As6'
_cell_volume   218.87
_cell_formula_units_Z   3
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
  Fe  Fe0  1  0.0  0.0  0.89  1.0
  Fe  Fe1  1  0.0  0.39  0.31  1.0
  Fe  Fe2  1  0.0  0.06  0.31  1.0
  Ni  Ni3  1  0.72  0.0  0.99  1.0
  Ni  Ni4  1  0.75  0.22  0.97  1.0
  Ni  Ni5  1  0.74  0.89  0.28  1.0
  Ni  Ni6  1  0.26  0.89  0.28  1.0
  Ni  Ni7  1  0.21  0.33  0.26  1.0
  Ni  Ni8  1  0.73  0.33  0.26  1.0
  As  As9  1  0.0  0.22  0.51  1.0
  As  As10  1  0.0  0.0  0.5  1.0
  As  As11  1  0.74  0.49  0.49  1.0
  As  As12  1  0.74  0.26  0.51  1.0
  As  As13  1  0.74  0.96  0.49  1.0
  As  As14  1  0.74  0.74  0.51  1.0

data_Fe(NiAs)2
_symmetry_space_group_name_H-M   P1
_cell_length_a   6.04
_cell_length_b   6.94
_cell_length_c   6.96
_cell_angle_alpha   119.92
_cell_angle_beta   115.7
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Fe(NiAs)2
_chemical_formula_sum   'Fe3 Ni6 As6'
_cell_volume   218.87
_cell_formula_units_Z   3
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
  Fe  Fe0  1  0.25  0.94  0.25  1.0
  Fe  Fe1  1  0.89  0.0  0.89  1.0
  Fe  Fe2  1  0.92  0.61  0.92  1.0
  Ni  Ni3  1  0.39  0.84  0.13  1.0
  Ni  Ni4  1  0.39  0.37  0.65  1.0
  Ni  Ni5  1  0.75  0.53  0.5  1.0
  Ni  Ni6  1  0.93  0.4  0.67  1.0
  Ni  Ni7  1  0.93  0.88  0.14  1.0
  Ni  Ni8  1  0.99  0.72  0.71  1.0
  As  As9  1  0.01  0.25  0.74  1.0
  As  As10  1  0.25  0.47  0.98  1.0
  As  As11  1  0.29  0.78  0.29  1.0
  As  As12  1  0.5  0.0  0.5  1.0
  As  As13  1  0.53  0.78  0.27  1.0
  As  As14  1  0.78  1.0  0.51  1.0

Fe Fe Fe Ni Ni Ni Ni Ni Ni As As As As As As
Fe(NiAs)2 crystallizes in the triclinic P1 space group. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 5-coordinate geometry to one Ni(1), one Ni(5), one As(2), one As(3), and one As(6) atom. The Fe(1)-Ni(1) bond length is 2.01 Å. The Fe(1)-Ni(5) bond length is 2.24 Å. The Fe(1)-As(2) bond length is 2.68 Å. The Fe(1)-As(3) bond length is 2.62 Å. The Fe(1)-As(6) bond length is 2.39 Å. In the second Fe site, Fe(2) is bonded in a 2-coordinate geometry to one Ni(1), one Ni(5), one Ni(6), and one As(4) atom. The Fe(2)-Ni(1) bond length is 2.13 Å. The Fe(2)-Ni(5) bond length is 1.70 Å. The Fe(2)-Ni(6) bond length is 1.66 Å. The Fe(2)-As(4) bond length is 2.17 Å. In the third Fe site, Fe(3) is bonded in a 4-coordinate geometry to one Ni(3), one Ni(5), one As(1), and one As(2) atom. The Fe(3)-Ni(3) bond length is 1.39 Å. The Fe(3)-Ni(5) bond length is 1.70 Å. The Fe(3)-As(1) bond length is 1.30 Å. The Fe(3)-As(2) bond length is 1.56 Å. There are six inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 3-coordinate geometry to one Fe(1), one Fe(2), and one Ni(2) atom. The Ni(1)-Ni(2) bond length is 1.48 Å. In the second Ni site, Ni(2) is bonded in a 3-coordinate geometry to one Ni(1), one Ni(6), and one As(5) atom. The Ni(2)-Ni(6) bond length is 1.79 Å. The Ni(2)-As(5) bond length is 2.85 Å. In the third Ni site, Ni(3) is bonded in a 2-coordinate geometry to one Fe(3), one As(4), and one As(5) atom. The Ni(3)-As(4) bond length is 2.26 Å. The Ni(3)-As(5) bond length is 1.31 Å. In the fourth Ni site, Ni(4) is bonded in a 2-coordinate geometry to one As(2) and one As(4) atom. The Ni(4)-As(2) bond length is 2.46 Å. The Ni(4)-As(4) bond length is 2.58 Å. In the fifth Ni site, Ni(5) is bonded in a 2-coordinate geometry to one Fe(1), one Fe(2), one Fe(3), and one As(6) atom. The Ni(5)-As(6) bond length is 2.86 Å. In the sixth Ni site, Ni(6) is bonded in a 2-coordinate geometry to one Fe(2), one Ni(2), one As(3), and one As(4) atom. The Ni(6)-As(3) bond length is 1.41 Å. The Ni(6)-As(4) bond length is 2.01 Å. There are six inequivalent As sites. In the first As site, As(1) is bonded in a single-bond geometry to one Fe(3) and one As(4) atom. The As(1)-As(4) bond length is 2.03 Å. In the second As site, As(2) is bonded in a 1-coordinate geometry to one Fe(1), one Fe(3), one Ni(4), and one As(6) atom. The As(2)-As(6) bond length is 1.63 Å. In the third As site, As(3) is bonded in a distorted single-bond geometry to one Fe(1), one Ni(6), one As(4), and one As(6) atom. The As(3)-As(4) bond length is 1.61 Å. The As(3)-As(6) bond length is 1.69 Å. In the fourth As site, As(4) is bonded in a distorted pentagonal bipyramidal geometry to one Fe(2), one Ni(3), one Ni(4), one Ni(6), one As(1), one As(3), and one As(5) atom. The As(4)-As(5) bond length is 2.06 Å. In the fifth As site, As(5) is bonded in a distorted single-bond geometry to one Ni(2), one Ni(3), one As(4), and one As(6) atom. The As(5)-As(6) bond length is 1.61 Å. In the sixth As site, As(6) is bonded in a 5-coordinate geometry to one Fe(1), one Ni(5), one As(2), one As(3), and one As(5) atom.