The material described by Pb2Ni(PO4)2 crystallizes in the monoclinic P2_1/c space group. Ni(1) is bonded to one O(2), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form NiO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a distorted rectangular see-saw-like geometry to one O(6), one O(7), and two equivalent O(4) atoms. In the second Pb site, Pb(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(6), one O(7), and one O(8) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-51°. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra and  an edgeedge with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-61°. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Pb(1) and one P(1) atom. In the second O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ni(1) and one P(2) atom. In the third O site, O(6) is bonded in a 1-coordinate geometry to one Ni(1), one Pb(1), one Pb(2), and one P(2) atom. In the fourth O site, O(7) is bonded in a 1-coordinate geometry to one Ni(1), one Pb(1), one Pb(2), and one P(2) atom. In the fifth O site, O(8) is bonded in a 3-coordinate geometry to one Ni(1), one Pb(2), and one P(2) atom. In the sixth O site, O(1) is bonded in a distorted single-bond geometry to one Pb(2) and one P(1) atom. In the seventh O site, O(2) is bonded in a 3-coordinate geometry to one Ni(1), one Pb(2), and one P(1) atom. In the eighth O site, O(3) is bonded in a 3-coordinate geometry to one Ni(1), one Pb(2), and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_NiP2(PbO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   15.685
_cell_length_b   5.361
_cell_length_c   8.561
_cell_angle_alpha   89.967
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   719.822
_cell_formula_units_Z   4
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  0.635  0.784  0.479  1.0
  Ni  Ni1  1  0.135  0.216  0.021  1.0
  Ni  Ni2  1  0.365  0.216  0.521  1.0
  Ni  Ni3  1  0.865  0.784  0.979  1.0
  P  P4  1  0.665  0.741  0.094  1.0
  P  P5  1  0.165  0.259  0.406  1.0
  P  P6  1  0.335  0.259  0.906  1.0
  P  P7  1  0.835  0.741  0.594  1.0
  P  P8  1  0.926  0.243  0.077  1.0
  P  P9  1  0.426  0.757  0.423  1.0
  P  P10  1  0.074  0.757  0.923  1.0
  P  P11  1  0.574  0.243  0.577  1.0
  Pb  Pb12  1  0.492  0.751  0.823  1.0
  Pb  Pb13  1  0.992  0.249  0.677  1.0
  Pb  Pb14  1  0.508  0.249  0.177  1.0
  Pb  Pb15  1  0.008  0.751  0.323  1.0
  Pb  Pb16  1  0.764  0.264  0.318  1.0
  Pb  Pb17  1  0.264  0.736  0.182  1.0
  Pb  Pb18  1  0.236  0.736  0.682  1.0
  Pb  Pb19  1  0.736  0.264  0.818  1.0
  O  O20  1  0.652  0.493  0.001  1.0
  O  O21  1  0.152  0.507  0.499  1.0
  O  O22  1  0.348  0.507  0.999  1.0
  O  O23  1  0.848  0.493  0.501  1.0
  O  O24  1  0.682  0.669  0.267  1.0
  O  O25  1  0.182  0.331  0.233  1.0
  O  O26  1  0.318  0.331  0.733  1.0
  O  O27  1  0.818  0.669  0.767  1.0
  O  O28  1  0.741  0.899  0.032  1.0
  O  O29  1  0.241  0.101  0.468  1.0
  O  O30  1  0.259  0.101  0.968  1.0
  O  O31  1  0.759  0.899  0.532  1.0
  O  O32  1  0.581  0.897  0.073  1.0
  O  O33  1  0.081  0.103  0.427  1.0
  O  O34  1  0.419  0.103  0.927  1.0
  O  O35  1  0.919  0.897  0.573  1.0
  O  O36  1  0.018  0.320  0.104  1.0
  O  O37  1  0.518  0.680  0.396  1.0
  O  O38  1  0.982  0.680  0.896  1.0
  O  O39  1  0.482  0.320  0.604  1.0
  O  O40  1  0.904  0.149  0.907  1.0
  O  O41  1  0.404  0.851  0.593  1.0
  O  O42  1  0.096  0.851  0.093  1.0
  O  O43  1  0.596  0.149  0.407  1.0
  O  O44  1  0.902  0.013  0.184  1.0
  O  O45  1  0.402  0.987  0.316  1.0
  O  O46  1  0.098  0.987  0.816  1.0
  O  O47  1  0.598  0.013  0.684  1.0
  O  O48  1  0.862  0.460  0.117  1.0
  O  O49  1  0.362  0.540  0.383  1.0
  O  O50  1  0.138  0.540  0.883  1.0
  O  O51  1  0.638  0.460  0.617  1.0
[/CIF]
.
The material described by Pb2Ni(PO4)2 crystallizes in the monoclinic P2_1/c space group. Ni(1) is bonded to one O(2), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form NiO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and  an edgeedge with one P(2)O4 tetrahedra. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a distorted rectangular see-saw-like geometry to one O(6), one O(7), and two equivalent O(4) atoms. In the second Pb site, Pb(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(6), one O(7), and one O(8) atom. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 45-51°. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Ni(1)O6 octahedra and  an edgeedge with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-61°. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Pb(1) and one P(1) atom. In the second O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ni(1) and one P(2) atom. In the third O site, O(6) is bonded in a 1-coordinate geometry to one Ni(1), one Pb(1), one Pb(2), and one P(2) atom. In the fourth O site, O(7) is bonded in a 1-coordinate geometry to one Ni(1), one Pb(1), one Pb(2), and one P(2) atom. In the fifth O site, O(8) is bonded in a 3-coordinate geometry to one Ni(1), one Pb(2), and one P(2) atom. In the sixth O site, O(1) is bonded in a distorted single-bond geometry to one Pb(2) and one P(1) atom. In the seventh O site, O(2) is bonded in a 3-coordinate geometry to one Ni(1), one Pb(2), and one P(1) atom. In the eighth O site, O(3) is bonded in a 3-coordinate geometry to one Ni(1), one Pb(2), and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_NiP2(PbO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   15.685
_cell_length_b   5.361
_cell_length_c   8.561
_cell_angle_alpha   89.967
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   719.822
_cell_formula_units_Z   4
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  0.635  0.784  0.479  1.0
  Ni  Ni1  1  0.135  0.216  0.021  1.0
  Ni  Ni2  1  0.365  0.216  0.521  1.0
  Ni  Ni3  1  0.865  0.784  0.979  1.0
  P  P4  1  0.665  0.741  0.094  1.0
  P  P5  1  0.165  0.259  0.406  1.0
  P  P6  1  0.335  0.259  0.906  1.0
  P  P7  1  0.835  0.741  0.594  1.0
  P  P8  1  0.926  0.243  0.077  1.0
  P  P9  1  0.426  0.757  0.423  1.0
  P  P10  1  0.074  0.757  0.923  1.0
  P  P11  1  0.574  0.243  0.577  1.0
  Pb  Pb12  1  0.492  0.751  0.823  1.0
  Pb  Pb13  1  0.992  0.249  0.677  1.0
  Pb  Pb14  1  0.508  0.249  0.177  1.0
  Pb  Pb15  1  0.008  0.751  0.323  1.0
  Pb  Pb16  1  0.764  0.264  0.318  1.0
  Pb  Pb17  1  0.264  0.736  0.182  1.0
  Pb  Pb18  1  0.236  0.736  0.682  1.0
  Pb  Pb19  1  0.736  0.264  0.818  1.0
  O  O20  1  0.652  0.493  0.001  1.0
  O  O21  1  0.152  0.507  0.499  1.0
  O  O22  1  0.348  0.507  0.999  1.0
  O  O23  1  0.848  0.493  0.501  1.0
  O  O24  1  0.682  0.669  0.267  1.0
  O  O25  1  0.182  0.331  0.233  1.0
  O  O26  1  0.318  0.331  0.733  1.0
  O  O27  1  0.818  0.669  0.767  1.0
  O  O28  1  0.741  0.899  0.032  1.0
  O  O29  1  0.241  0.101  0.468  1.0
  O  O30  1  0.259  0.101  0.968  1.0
  O  O31  1  0.759  0.899  0.532  1.0
  O  O32  1  0.581  0.897  0.073  1.0
  O  O33  1  0.081  0.103  0.427  1.0
  O  O34  1  0.419  0.103  0.927  1.0
  O  O35  1  0.919  0.897  0.573  1.0
  O  O36  1  0.018  0.320  0.104  1.0
  O  O37  1  0.518  0.680  0.396  1.0
  O  O38  1  0.982  0.680  0.896  1.0
  O  O39  1  0.482  0.320  0.604  1.0
  O  O40  1  0.904  0.149  0.907  1.0
  O  O41  1  0.404  0.851  0.593  1.0
  O  O42  1  0.096  0.851  0.093  1.0
  O  O43  1  0.596  0.149  0.407  1.0
  O  O44  1  0.902  0.013  0.184  1.0
  O  O45  1  0.402  0.987  0.316  1.0
  O  O46  1  0.098  0.987  0.816  1.0
  O  O47  1  0.598  0.013  0.684  1.0
  O  O48  1  0.862  0.460  0.117  1.0
  O  O49  1  0.362  0.540  0.383  1.0
  O  O50  1  0.138  0.540  0.883  1.0
  O  O51  1  0.638  0.460  0.617  1.0
[/CIF]
.