The compound described by Fe3NiAs4 is Modderite-derived structured and crystallizes in the monoclinic Pm space group. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to one As(1), one As(2), two equivalent As(3), and two equivalent As(4) atoms. In the second Fe site, Fe(2) is bonded to one As(3), one As(4), two equivalent As(1), and two equivalent As(2) atoms to form distorted edge-sharing FeAs6 octahedra. In the third Fe site, Fe(3) is bonded in a 6-coordinate geometry to one As(3), one As(4), two equivalent As(1), and two equivalent As(2) atoms. Ni(1) is bonded in a 6-coordinate geometry to one As(1), one As(2), two equivalent As(3), and two equivalent As(4) atoms. There are four inequivalent As sites. In the first As site, As(1) is bonded in a 6-coordinate geometry to one Fe(1), two equivalent Fe(2), two equivalent Fe(3), and one Ni(1) atom. In the second As site, As(2) is bonded in a 6-coordinate geometry to one Fe(1), two equivalent Fe(2), two equivalent Fe(3), and one Ni(1) atom. In the third As site, As(3) is bonded in a 6-coordinate geometry to one Fe(2), one Fe(3), two equivalent Fe(1), and two equivalent Ni(1) atoms. In the fourth As site, As(4) is bonded in a 6-coordinate geometry to one Fe(2), one Fe(3), two equivalent Fe(1), and two equivalent Ni(1) atoms. is represented by the CIF card [CIF]
data_Fe3NiAs4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.433
_cell_length_b   5.225
_cell_length_c   5.880
_cell_angle_alpha   89.644
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   105.494
_cell_formula_units_Z   1
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  0.500  0.998  0.200  1.0
  Fe  Fe1  1  0.000  0.500  0.710  1.0
  Fe  Fe2  1  0.000  1.000  0.797  1.0
  Ni  Ni3  1  0.500  0.500  0.299  1.0
  As  As4  1  0.500  0.708  0.909  1.0
  As  As5  1  0.500  0.195  0.586  1.0
  As  As6  1  0.000  0.291  0.079  1.0
  As  As7  1  0.000  0.808  0.420  1.0
[/CIF]
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The compound described by Fe3NiAs4 is Modderite-derived structured and crystallizes in the monoclinic Pm space group. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 6-coordinate geometry to one As(1), one As(2), two equivalent As(3), and two equivalent As(4) atoms. In the second Fe site, Fe(2) is bonded to one As(3), one As(4), two equivalent As(1), and two equivalent As(2) atoms to form distorted edge-sharing FeAs6 octahedra. In the third Fe site, Fe(3) is bonded in a 6-coordinate geometry to one As(3), one As(4), two equivalent As(1), and two equivalent As(2) atoms. Ni(1) is bonded in a 6-coordinate geometry to one As(1), one As(2), two equivalent As(3), and two equivalent As(4) atoms. There are four inequivalent As sites. In the first As site, As(1) is bonded in a 6-coordinate geometry to one Fe(1), two equivalent Fe(2), two equivalent Fe(3), and one Ni(1) atom. In the second As site, As(2) is bonded in a 6-coordinate geometry to one Fe(1), two equivalent Fe(2), two equivalent Fe(3), and one Ni(1) atom. In the third As site, As(3) is bonded in a 6-coordinate geometry to one Fe(2), one Fe(3), two equivalent Fe(1), and two equivalent Ni(1) atoms. In the fourth As site, As(4) is bonded in a 6-coordinate geometry to one Fe(2), one Fe(3), two equivalent Fe(1), and two equivalent Ni(1) atoms. is represented by the CIF card [CIF]
data_Fe3NiAs4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.433
_cell_length_b   5.225
_cell_length_c   5.880
_cell_angle_alpha   89.644
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   105.494
_cell_formula_units_Z   1
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  0.500  0.998  0.200  1.0
  Fe  Fe1  1  0.000  0.500  0.710  1.0
  Fe  Fe2  1  0.000  1.000  0.797  1.0
  Ni  Ni3  1  0.500  0.500  0.299  1.0
  As  As4  1  0.500  0.708  0.909  1.0
  As  As5  1  0.500  0.195  0.586  1.0
  As  As6  1  0.000  0.291  0.079  1.0
  As  As7  1  0.000  0.808  0.420  1.0
[/CIF]
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