The material described by Ni5As2 crystallizes in the hexagonal P6_3cm space group. There are six inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one As(1) and three equivalent As(3) atoms to form distorted corner-sharing NiAs4 tetrahedra. In the second Ni site, Ni(2) is bonded to three equivalent Ni(4), one As(2), and three equivalent As(3) atoms to form distorted NiNi3As4 tetrahedra that share corners with three equivalent Ni(1)As4 tetrahedra and edges with three equivalent Ni(2)Ni3As4 tetrahedra. In the third Ni site, Ni(3) is bonded in a 3-coordinate geometry to three equivalent Ni(4), one As(1), and two equivalent As(3) atoms. In the fourth Ni site, Ni(4) is bonded in a 13-coordinate geometry to one Ni(6), two equivalent Ni(2), three equivalent Ni(3), three equivalent Ni(5), one As(1), one As(3), and two equivalent As(2) atoms. In the fifth Ni site, Ni(5) is bonded in a 4-coordinate geometry to three equivalent Ni(4), one As(1), one As(3), and two equivalent As(2) atoms. In the sixth Ni site, Ni(6) is bonded in a 1-coordinate geometry to one Ni(4), two equivalent As(2), and three equivalent As(3) atoms. There are three inequivalent As sites. In the first As site, As(2) is bonded in a 10-coordinate geometry to one Ni(2), three equivalent Ni(4), three equivalent Ni(5), and three equivalent Ni(6) atoms. In the second As site, As(3) is bonded in a 10-coordinate geometry to one Ni(1), one Ni(4), one Ni(5), two equivalent Ni(2), two equivalent Ni(3), and three equivalent Ni(6) atoms. In the third As site, As(1) is bonded in a 10-coordinate geometry to one Ni(1), three equivalent Ni(3), three equivalent Ni(4), and three equivalent Ni(5) atoms. is represented by the CIF file [CIF]
data_Ni5As2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.742
_cell_length_b   6.742
_cell_length_c   12.453
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   490.247
_cell_formula_units_Z   6
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
  Ni  Ni0  1  0.000  0.000  0.949  1.0
  Ni  Ni1  1  0.000  0.000  0.449  1.0
  Ni  Ni2  1  0.333  0.667  0.095  1.0
  Ni  Ni3  1  0.667  0.333  0.595  1.0
  Ni  Ni4  1  0.333  0.667  0.595  1.0
  Ni  Ni5  1  0.667  0.333  0.095  1.0
  Ni  Ni6  1  0.250  0.000  0.121  1.0
  Ni  Ni7  1  0.250  0.250  0.621  1.0
  Ni  Ni8  1  0.000  0.750  0.621  1.0
  Ni  Ni9  1  0.000  0.250  0.121  1.0
  Ni  Ni10  1  0.750  0.750  0.121  1.0
  Ni  Ni11  1  0.750  0.000  0.621  1.0
  Ni  Ni12  1  0.624  0.000  0.219  1.0
  Ni  Ni13  1  0.624  0.624  0.719  1.0
  Ni  Ni14  1  0.000  0.376  0.719  1.0
  Ni  Ni15  1  0.000  0.624  0.219  1.0
  Ni  Ni16  1  0.376  0.376  0.219  1.0
  Ni  Ni17  1  0.376  0.000  0.719  1.0
  Ni  Ni18  1  0.311  0.000  0.329  1.0
  Ni  Ni19  1  0.311  0.311  0.829  1.0
  Ni  Ni20  1  0.000  0.689  0.829  1.0
  Ni  Ni21  1  0.000  0.311  0.329  1.0
  Ni  Ni22  1  0.689  0.689  0.329  1.0
  Ni  Ni23  1  0.689  0.000  0.829  1.0
  Ni  Ni24  1  0.626  0.000  0.433  1.0
  Ni  Ni25  1  0.626  0.626  0.933  1.0
  Ni  Ni26  1  0.000  0.374  0.933  1.0
  Ni  Ni27  1  0.000  0.626  0.433  1.0
  Ni  Ni28  1  0.374  0.374  0.433  1.0
  Ni  Ni29  1  0.374  0.000  0.933  1.0
  As  As30  1  0.000  0.000  0.255  1.0
  As  As31  1  0.000  0.000  0.755  1.0
  As  As32  1  0.333  0.667  0.295  1.0
  As  As33  1  0.667  0.333  0.795  1.0
  As  As34  1  0.333  0.667  0.795  1.0
  As  As35  1  0.667  0.333  0.295  1.0
  As  As36  1  0.669  0.000  0.023  1.0
  As  As37  1  0.669  0.669  0.523  1.0
  As  As38  1  0.000  0.331  0.523  1.0
  As  As39  1  0.000  0.669  0.023  1.0
  As  As40  1  0.331  0.331  0.023  1.0
  As  As41  1  0.331  0.000  0.523  1.0
[/CIF]
.
The material described by Ni5As2 crystallizes in the hexagonal P6_3cm space group. There are six inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one As(1) and three equivalent As(3) atoms to form distorted corner-sharing NiAs4 tetrahedra. In the second Ni site, Ni(2) is bonded to three equivalent Ni(4), one As(2), and three equivalent As(3) atoms to form distorted NiNi3As4 tetrahedra that share corners with three equivalent Ni(1)As4 tetrahedra and edges with three equivalent Ni(2)Ni3As4 tetrahedra. In the third Ni site, Ni(3) is bonded in a 3-coordinate geometry to three equivalent Ni(4), one As(1), and two equivalent As(3) atoms. In the fourth Ni site, Ni(4) is bonded in a 13-coordinate geometry to one Ni(6), two equivalent Ni(2), three equivalent Ni(3), three equivalent Ni(5), one As(1), one As(3), and two equivalent As(2) atoms. In the fifth Ni site, Ni(5) is bonded in a 4-coordinate geometry to three equivalent Ni(4), one As(1), one As(3), and two equivalent As(2) atoms. In the sixth Ni site, Ni(6) is bonded in a 1-coordinate geometry to one Ni(4), two equivalent As(2), and three equivalent As(3) atoms. There are three inequivalent As sites. In the first As site, As(2) is bonded in a 10-coordinate geometry to one Ni(2), three equivalent Ni(4), three equivalent Ni(5), and three equivalent Ni(6) atoms. In the second As site, As(3) is bonded in a 10-coordinate geometry to one Ni(1), one Ni(4), one Ni(5), two equivalent Ni(2), two equivalent Ni(3), and three equivalent Ni(6) atoms. In the third As site, As(1) is bonded in a 10-coordinate geometry to one Ni(1), three equivalent Ni(3), three equivalent Ni(4), and three equivalent Ni(5) atoms. is represented by the CIF file [CIF]
data_Ni5As2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.742
_cell_length_b   6.742
_cell_length_c   12.453
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   490.247
_cell_formula_units_Z   6
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
  Ni  Ni0  1  0.000  0.000  0.949  1.0
  Ni  Ni1  1  0.000  0.000  0.449  1.0
  Ni  Ni2  1  0.333  0.667  0.095  1.0
  Ni  Ni3  1  0.667  0.333  0.595  1.0
  Ni  Ni4  1  0.333  0.667  0.595  1.0
  Ni  Ni5  1  0.667  0.333  0.095  1.0
  Ni  Ni6  1  0.250  0.000  0.121  1.0
  Ni  Ni7  1  0.250  0.250  0.621  1.0
  Ni  Ni8  1  0.000  0.750  0.621  1.0
  Ni  Ni9  1  0.000  0.250  0.121  1.0
  Ni  Ni10  1  0.750  0.750  0.121  1.0
  Ni  Ni11  1  0.750  0.000  0.621  1.0
  Ni  Ni12  1  0.624  0.000  0.219  1.0
  Ni  Ni13  1  0.624  0.624  0.719  1.0
  Ni  Ni14  1  0.000  0.376  0.719  1.0
  Ni  Ni15  1  0.000  0.624  0.219  1.0
  Ni  Ni16  1  0.376  0.376  0.219  1.0
  Ni  Ni17  1  0.376  0.000  0.719  1.0
  Ni  Ni18  1  0.311  0.000  0.329  1.0
  Ni  Ni19  1  0.311  0.311  0.829  1.0
  Ni  Ni20  1  0.000  0.689  0.829  1.0
  Ni  Ni21  1  0.000  0.311  0.329  1.0
  Ni  Ni22  1  0.689  0.689  0.329  1.0
  Ni  Ni23  1  0.689  0.000  0.829  1.0
  Ni  Ni24  1  0.626  0.000  0.433  1.0
  Ni  Ni25  1  0.626  0.626  0.933  1.0
  Ni  Ni26  1  0.000  0.374  0.933  1.0
  Ni  Ni27  1  0.000  0.626  0.433  1.0
  Ni  Ni28  1  0.374  0.374  0.433  1.0
  Ni  Ni29  1  0.374  0.000  0.933  1.0
  As  As30  1  0.000  0.000  0.255  1.0
  As  As31  1  0.000  0.000  0.755  1.0
  As  As32  1  0.333  0.667  0.295  1.0
  As  As33  1  0.667  0.333  0.795  1.0
  As  As34  1  0.333  0.667  0.795  1.0
  As  As35  1  0.667  0.333  0.295  1.0
  As  As36  1  0.669  0.000  0.023  1.0
  As  As37  1  0.669  0.669  0.523  1.0
  As  As38  1  0.000  0.331  0.523  1.0
  As  As39  1  0.000  0.669  0.023  1.0
  As  As40  1  0.331  0.331  0.023  1.0
  As  As41  1  0.331  0.000  0.523  1.0
[/CIF]
.