The compound described by Na2Ni(PO5)4 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded in a 3-coordinate geometry to one O(1), one O(4), one O(7), one O(8), and one O(9) atom. Ni(1) is bonded to two equivalent O(10), two equivalent O(3), and two equivalent O(6) atoms to form NiO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. 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  a cornercorner with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 60°. There are ten inequivalent O sites. In the first O site, O(6) is bonded in a bent 120 degrees geometry to one Ni(1) and one P(2) atom. In the second O site, O(7) is bonded in a bent 150 degrees geometry to one Na(1) and one P(2) atom. In the third O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Na(1) and one P(2) atom. In the fourth O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Na(1) and one P(1) atom. In the fifth O site, O(9) is bonded in a bent 120 degrees geometry to one Na(1) and one O(4) atom. In the sixth O site, O(2) is bonded in a single-bond geometry to one P(1) atom. In the seventh O site, O(10) is bonded in a distorted single-bond geometry to one Ni(1) atom. In the eighth O site, O(3) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(1) atom. In the ninth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Na(1) and one O(9) atom. In the tenth O site, O(5) is bonded in a single-bond geometry to one P(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2Ni(PO5)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.798
_cell_length_b   7.602
_cell_length_c   11.731
_cell_angle_alpha   59.954
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   833.533
_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
  Na  Na0  1  0.340  0.705  1.000  1.0
  Na  Na1  1  0.160  0.705  0.500  1.0
  Na  Na2  1  0.660  0.295  0.000  1.0
  Na  Na3  1  0.840  0.295  0.500  1.0
  Ni  Ni4  1  0.500  0.000  0.500  1.0
  Ni  Ni5  1  0.000  0.000  0.000  1.0
  P  P6  1  0.265  0.214  0.600  1.0
  P  P7  1  0.235  0.214  0.100  1.0
  P  P8  1  0.735  0.786  0.400  1.0
  P  P9  1  0.765  0.786  0.900  1.0
  P  P10  1  0.049  0.562  0.203  1.0
  P  P11  1  0.451  0.562  0.703  1.0
  P  P12  1  0.951  0.438  0.797  1.0
  P  P13  1  0.549  0.438  0.297  1.0
  O  O14  1  0.674  0.618  0.965  1.0
  O  O15  1  0.826  0.618  0.465  1.0
  O  O16  1  0.326  0.382  0.035  1.0
  O  O17  1  0.174  0.382  0.535  1.0
  O  O18  1  0.282  0.099  0.745  1.0
  O  O19  1  0.218  0.099  0.245  1.0
  O  O20  1  0.718  0.901  0.255  1.0
  O  O21  1  0.782  0.901  0.755  1.0
  O  O22  1  0.839  0.841  0.987  1.0
  O  O23  1  0.661  0.841  0.487  1.0
  O  O24  1  0.161  0.159  0.013  1.0
  O  O25  1  0.339  0.159  0.513  1.0
  O  O26  1  0.600  0.046  0.883  1.0
  O  O27  1  0.900  0.046  0.383  1.0
  O  O28  1  0.400  0.954  0.117  1.0
  O  O29  1  0.100  0.954  0.617  1.0
  O  O30  1  0.967  0.481  0.132  1.0
  O  O31  1  0.533  0.481  0.632  1.0
  O  O32  1  0.033  0.519  0.868  1.0
  O  O33  1  0.467  0.519  0.368  1.0
  O  O34  1  0.021  0.785  0.175  1.0
  O  O35  1  0.479  0.785  0.675  1.0
  O  O36  1  0.979  0.215  0.825  1.0
  O  O37  1  0.521  0.215  0.325  1.0
  O  O38  1  0.686  0.419  0.335  1.0
  O  O39  1  0.814  0.419  0.835  1.0
  O  O40  1  0.314  0.581  0.665  1.0
  O  O41  1  0.186  0.581  0.165  1.0
  O  O42  1  0.015  0.411  0.347  1.0
  O  O43  1  0.485  0.411  0.847  1.0
  O  O44  1  0.985  0.589  0.653  1.0
  O  O45  1  0.515  0.589  0.153  1.0
  O  O46  1  0.010  0.981  0.671  1.0
  O  O47  1  0.490  0.981  0.171  1.0
  O  O48  1  0.990  0.019  0.329  1.0
  O  O49  1  0.510  0.019  0.829  1.0
  O  O50  1  0.600  0.119  0.561  1.0
  O  O51  1  0.900  0.119  0.061  1.0
  O  O52  1  0.400  0.881  0.439  1.0
  O  O53  1  0.100  0.881  0.939  1.0
[/CIF]
.
The compound described by Na2Ni(PO5)4 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded in a 3-coordinate geometry to one O(1), one O(4), one O(7), one O(8), and one O(9) atom. Ni(1) is bonded to two equivalent O(10), two equivalent O(3), and two equivalent O(6) atoms to form NiO6 octahedra that share corners with two equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. 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  a cornercorner with one Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 60°. There are ten inequivalent O sites. In the first O site, O(6) is bonded in a bent 120 degrees geometry to one Ni(1) and one P(2) atom. In the second O site, O(7) is bonded in a bent 150 degrees geometry to one Na(1) and one P(2) atom. In the third O site, O(8) is bonded in a distorted bent 150 degrees geometry to one Na(1) and one P(2) atom. In the fourth O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Na(1) and one P(1) atom. In the fifth O site, O(9) is bonded in a bent 120 degrees geometry to one Na(1) and one O(4) atom. In the sixth O site, O(2) is bonded in a single-bond geometry to one P(1) atom. In the seventh O site, O(10) is bonded in a distorted single-bond geometry to one Ni(1) atom. In the eighth O site, O(3) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(1) atom. In the ninth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Na(1) and one O(9) atom. In the tenth O site, O(5) is bonded in a single-bond geometry to one P(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2Ni(PO5)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.798
_cell_length_b   7.602
_cell_length_c   11.731
_cell_angle_alpha   59.954
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   833.533
_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
  Na  Na0  1  0.340  0.705  1.000  1.0
  Na  Na1  1  0.160  0.705  0.500  1.0
  Na  Na2  1  0.660  0.295  0.000  1.0
  Na  Na3  1  0.840  0.295  0.500  1.0
  Ni  Ni4  1  0.500  0.000  0.500  1.0
  Ni  Ni5  1  0.000  0.000  0.000  1.0
  P  P6  1  0.265  0.214  0.600  1.0
  P  P7  1  0.235  0.214  0.100  1.0
  P  P8  1  0.735  0.786  0.400  1.0
  P  P9  1  0.765  0.786  0.900  1.0
  P  P10  1  0.049  0.562  0.203  1.0
  P  P11  1  0.451  0.562  0.703  1.0
  P  P12  1  0.951  0.438  0.797  1.0
  P  P13  1  0.549  0.438  0.297  1.0
  O  O14  1  0.674  0.618  0.965  1.0
  O  O15  1  0.826  0.618  0.465  1.0
  O  O16  1  0.326  0.382  0.035  1.0
  O  O17  1  0.174  0.382  0.535  1.0
  O  O18  1  0.282  0.099  0.745  1.0
  O  O19  1  0.218  0.099  0.245  1.0
  O  O20  1  0.718  0.901  0.255  1.0
  O  O21  1  0.782  0.901  0.755  1.0
  O  O22  1  0.839  0.841  0.987  1.0
  O  O23  1  0.661  0.841  0.487  1.0
  O  O24  1  0.161  0.159  0.013  1.0
  O  O25  1  0.339  0.159  0.513  1.0
  O  O26  1  0.600  0.046  0.883  1.0
  O  O27  1  0.900  0.046  0.383  1.0
  O  O28  1  0.400  0.954  0.117  1.0
  O  O29  1  0.100  0.954  0.617  1.0
  O  O30  1  0.967  0.481  0.132  1.0
  O  O31  1  0.533  0.481  0.632  1.0
  O  O32  1  0.033  0.519  0.868  1.0
  O  O33  1  0.467  0.519  0.368  1.0
  O  O34  1  0.021  0.785  0.175  1.0
  O  O35  1  0.479  0.785  0.675  1.0
  O  O36  1  0.979  0.215  0.825  1.0
  O  O37  1  0.521  0.215  0.325  1.0
  O  O38  1  0.686  0.419  0.335  1.0
  O  O39  1  0.814  0.419  0.835  1.0
  O  O40  1  0.314  0.581  0.665  1.0
  O  O41  1  0.186  0.581  0.165  1.0
  O  O42  1  0.015  0.411  0.347  1.0
  O  O43  1  0.485  0.411  0.847  1.0
  O  O44  1  0.985  0.589  0.653  1.0
  O  O45  1  0.515  0.589  0.153  1.0
  O  O46  1  0.010  0.981  0.671  1.0
  O  O47  1  0.490  0.981  0.171  1.0
  O  O48  1  0.990  0.019  0.329  1.0
  O  O49  1  0.510  0.019  0.829  1.0
  O  O50  1  0.600  0.119  0.561  1.0
  O  O51  1  0.900  0.119  0.061  1.0
  O  O52  1  0.400  0.881  0.439  1.0
  O  O53  1  0.100  0.881  0.939  1.0
[/CIF]
.