The crystal structure described by MgNi2(PO4)2 crystallizes in the monoclinic C2/c space group. Mg(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(8) atom. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form NiO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a cornercorner with one Ni(3)O4 trigonal pyramid. In the second Ni site, Ni(2) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(4) atoms. In the third Ni site, Ni(3) is bonded to two equivalent O(5) and two equivalent O(7) atoms to form NiO4 trigonal pyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent Ni(1)O5 trigonal bipyramids. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Ni(1)O5 trigonal bipyramids and  a cornercorner with one Ni(3)O4 trigonal pyramid. In the second P site, P(2) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Ni(1)O5 trigonal bipyramids and  a cornercorner with one Ni(3)O4 trigonal pyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(2), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(1), and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Ni(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Ni(1), one Ni(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ni(3) and one P(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Mg(1), one Ni(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Ni(1), one Ni(3), and one P(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Mg(1) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgNi2(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.882
_cell_length_b   8.882
_cell_length_c   16.347
_cell_angle_alpha   61.181
_cell_angle_beta   61.181
_cell_angle_gamma   32.288
_symmetry_Int_Tables_number   1
_cell_volume   595.940
_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
  Mg  Mg0  1  0.443  0.856  0.373  1.0
  Mg  Mg1  1  0.144  0.557  0.127  1.0
  Mg  Mg2  1  0.856  0.443  0.873  1.0
  Mg  Mg3  1  0.557  0.144  0.627  1.0
  Ni  Ni4  1  0.200  0.604  0.469  1.0
  Ni  Ni5  1  0.396  0.800  0.031  1.0
  Ni  Ni6  1  0.800  0.396  0.531  1.0
  Ni  Ni7  1  0.500  0.000  0.500  1.0
  Ni  Ni8  1  0.604  0.200  0.969  1.0
  Ni  Ni9  1  0.610  0.390  0.750  1.0
  Ni  Ni10  1  0.390  0.610  0.250  1.0
  Ni  Ni11  1  0.000  0.500  0.000  1.0
  P  P12  1  0.069  0.511  0.358  1.0
  P  P13  1  0.777  0.178  0.113  1.0
  P  P14  1  0.931  0.489  0.642  1.0
  P  P15  1  0.178  0.777  0.613  1.0
  P  P16  1  0.511  0.069  0.858  1.0
  P  P17  1  0.489  0.931  0.142  1.0
  P  P18  1  0.223  0.822  0.887  1.0
  P  P19  1  0.822  0.223  0.387  1.0
  O  O20  1  0.705  0.814  0.603  1.0
  O  O21  1  0.774  0.408  0.413  1.0
  O  O22  1  0.814  0.705  0.103  1.0
  O  O23  1  0.795  0.360  0.037  1.0
  O  O24  1  0.207  0.338  0.562  1.0
  O  O25  1  0.636  0.264  0.210  1.0
  O  O26  1  0.640  0.205  0.463  1.0
  O  O27  1  0.859  0.089  0.611  1.0
  O  O28  1  0.205  0.640  0.963  1.0
  O  O29  1  0.592  0.226  0.087  1.0
  O  O30  1  0.846  0.392  0.642  1.0
  O  O31  1  0.593  0.003  0.765  1.0
  O  O32  1  0.226  0.592  0.587  1.0
  O  O33  1  0.089  0.859  0.111  1.0
  O  O34  1  0.295  0.186  0.397  1.0
  O  O35  1  0.154  0.608  0.358  1.0
  O  O36  1  0.003  0.593  0.265  1.0
  O  O37  1  0.360  0.795  0.537  1.0
  O  O38  1  0.392  0.846  0.142  1.0
  O  O39  1  0.407  0.997  0.235  1.0
  O  O40  1  0.911  0.141  0.889  1.0
  O  O41  1  0.338  0.207  0.062  1.0
  O  O42  1  0.141  0.911  0.389  1.0
  O  O43  1  0.264  0.636  0.710  1.0
  O  O44  1  0.408  0.774  0.913  1.0
  O  O45  1  0.186  0.295  0.897  1.0
  O  O46  1  0.997  0.407  0.735  1.0
  O  O47  1  0.662  0.793  0.938  1.0
  O  O48  1  0.793  0.662  0.438  1.0
  O  O49  1  0.736  0.364  0.290  1.0
  O  O50  1  0.364  0.736  0.790  1.0
  O  O51  1  0.608  0.154  0.858  1.0
[/CIF]
.
The crystal structure described by MgNi2(PO4)2 crystallizes in the monoclinic C2/c space group. Mg(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(8) atom. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form NiO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra, and  a cornercorner with one Ni(3)O4 trigonal pyramid. In the second Ni site, Ni(2) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(4) atoms. In the third Ni site, Ni(3) is bonded to two equivalent O(5) and two equivalent O(7) atoms to form NiO4 trigonal pyramids that share corners with two equivalent P(1)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent Ni(1)O5 trigonal bipyramids. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Ni(1)O5 trigonal bipyramids and  a cornercorner with one Ni(3)O4 trigonal pyramid. In the second P site, P(2) is bonded to one O(2), one O(3), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with three equivalent Ni(1)O5 trigonal bipyramids and  a cornercorner with one Ni(3)O4 trigonal pyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(2), and one P(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(1), and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Ni(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Ni(1), one Ni(2), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ni(3) and one P(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Mg(1), one Ni(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Ni(1), one Ni(3), and one P(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Mg(1) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgNi2(PO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.882
_cell_length_b   8.882
_cell_length_c   16.347
_cell_angle_alpha   61.181
_cell_angle_beta   61.181
_cell_angle_gamma   32.288
_symmetry_Int_Tables_number   1
_cell_volume   595.940
_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
  Mg  Mg0  1  0.443  0.856  0.373  1.0
  Mg  Mg1  1  0.144  0.557  0.127  1.0
  Mg  Mg2  1  0.856  0.443  0.873  1.0
  Mg  Mg3  1  0.557  0.144  0.627  1.0
  Ni  Ni4  1  0.200  0.604  0.469  1.0
  Ni  Ni5  1  0.396  0.800  0.031  1.0
  Ni  Ni6  1  0.800  0.396  0.531  1.0
  Ni  Ni7  1  0.500  0.000  0.500  1.0
  Ni  Ni8  1  0.604  0.200  0.969  1.0
  Ni  Ni9  1  0.610  0.390  0.750  1.0
  Ni  Ni10  1  0.390  0.610  0.250  1.0
  Ni  Ni11  1  0.000  0.500  0.000  1.0
  P  P12  1  0.069  0.511  0.358  1.0
  P  P13  1  0.777  0.178  0.113  1.0
  P  P14  1  0.931  0.489  0.642  1.0
  P  P15  1  0.178  0.777  0.613  1.0
  P  P16  1  0.511  0.069  0.858  1.0
  P  P17  1  0.489  0.931  0.142  1.0
  P  P18  1  0.223  0.822  0.887  1.0
  P  P19  1  0.822  0.223  0.387  1.0
  O  O20  1  0.705  0.814  0.603  1.0
  O  O21  1  0.774  0.408  0.413  1.0
  O  O22  1  0.814  0.705  0.103  1.0
  O  O23  1  0.795  0.360  0.037  1.0
  O  O24  1  0.207  0.338  0.562  1.0
  O  O25  1  0.636  0.264  0.210  1.0
  O  O26  1  0.640  0.205  0.463  1.0
  O  O27  1  0.859  0.089  0.611  1.0
  O  O28  1  0.205  0.640  0.963  1.0
  O  O29  1  0.592  0.226  0.087  1.0
  O  O30  1  0.846  0.392  0.642  1.0
  O  O31  1  0.593  0.003  0.765  1.0
  O  O32  1  0.226  0.592  0.587  1.0
  O  O33  1  0.089  0.859  0.111  1.0
  O  O34  1  0.295  0.186  0.397  1.0
  O  O35  1  0.154  0.608  0.358  1.0
  O  O36  1  0.003  0.593  0.265  1.0
  O  O37  1  0.360  0.795  0.537  1.0
  O  O38  1  0.392  0.846  0.142  1.0
  O  O39  1  0.407  0.997  0.235  1.0
  O  O40  1  0.911  0.141  0.889  1.0
  O  O41  1  0.338  0.207  0.062  1.0
  O  O42  1  0.141  0.911  0.389  1.0
  O  O43  1  0.264  0.636  0.710  1.0
  O  O44  1  0.408  0.774  0.913  1.0
  O  O45  1  0.186  0.295  0.897  1.0
  O  O46  1  0.997  0.407  0.735  1.0
  O  O47  1  0.662  0.793  0.938  1.0
  O  O48  1  0.793  0.662  0.438  1.0
  O  O49  1  0.736  0.364  0.290  1.0
  O  O50  1  0.364  0.736  0.790  1.0
  O  O51  1  0.608  0.154  0.858  1.0
[/CIF]
.