The material structure described by MgNiP2O7 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to one O(1), one O(3), one O(5), one O(7), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Ni(1)O5 trigonal bipyramids. Ni(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(7) atom to form NiO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and edges with two equivalent Mg(1)O6 octahedra. 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(6) atom to form PO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with three equivalent Ni(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 48-51°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with four equivalent Mg(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with two equivalent Ni(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 32-53°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(1), and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one Ni(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(1), and one P(2) atom. is represented by the CIF file [CIF]
data_MgNiP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.530
_cell_length_b   6.420
_cell_length_c   7.361
_cell_angle_alpha   82.501
_cell_angle_beta   87.466
_cell_angle_gamma   71.559
_symmetry_Int_Tables_number   1
_cell_volume   245.795
_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
  Mg  Mg0  1  0.331  0.658  0.654  1.0
  Mg  Mg1  1  0.669  0.342  0.346  1.0
  Ni  Ni2  1  0.254  0.162  0.203  1.0
  Ni  Ni3  1  0.746  0.838  0.797  1.0
  O  O4  1  0.103  0.693  0.896  1.0
  O  O5  1  0.897  0.307  0.104  1.0
  O  O6  1  0.294  0.868  0.122  1.0
  O  O7  1  0.706  0.132  0.878  1.0
  O  O8  1  0.353  0.452  0.171  1.0
  O  O9  1  0.647  0.548  0.829  1.0
  O  O10  1  0.606  0.647  0.431  1.0
  O  O11  1  0.394  0.353  0.569  1.0
  O  O12  1  0.052  0.214  0.456  1.0
  O  O13  1  0.948  0.786  0.544  1.0
  O  O14  1  0.079  0.280  0.793  1.0
  O  O15  1  0.921  0.720  0.207  1.0
  O  O16  1  0.607  0.044  0.326  1.0
  O  O17  1  0.393  0.956  0.674  1.0
  P  P18  1  0.185  0.687  0.095  1.0
  P  P19  1  0.815  0.313  0.905  1.0
  P  P20  1  0.234  0.198  0.614  1.0
  P  P21  1  0.766  0.802  0.386  1.0
[/CIF]
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The material structure described by MgNiP2O7 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to one O(1), one O(3), one O(5), one O(7), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra, corners with four equivalent P(2)O4 tetrahedra,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Ni(1)O5 trigonal bipyramids. Ni(1) is bonded to one O(1), one O(2), one O(3), one O(5), and one O(7) atom to form NiO5 trigonal bipyramids that share corners with two equivalent P(2)O4 tetrahedra, corners with three equivalent P(1)O4 tetrahedra, and edges with two equivalent Mg(1)O6 octahedra. 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(6) atom to form PO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with three equivalent Ni(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 48-51°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with four equivalent Mg(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and corners with two equivalent Ni(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 32-53°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(1), and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ni(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Mg(1) and one P(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one Ni(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one P(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Mg(1), one Ni(1), and one P(2) atom. is represented by the CIF file [CIF]
data_MgNiP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.530
_cell_length_b   6.420
_cell_length_c   7.361
_cell_angle_alpha   82.501
_cell_angle_beta   87.466
_cell_angle_gamma   71.559
_symmetry_Int_Tables_number   1
_cell_volume   245.795
_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
  Mg  Mg0  1  0.331  0.658  0.654  1.0
  Mg  Mg1  1  0.669  0.342  0.346  1.0
  Ni  Ni2  1  0.254  0.162  0.203  1.0
  Ni  Ni3  1  0.746  0.838  0.797  1.0
  O  O4  1  0.103  0.693  0.896  1.0
  O  O5  1  0.897  0.307  0.104  1.0
  O  O6  1  0.294  0.868  0.122  1.0
  O  O7  1  0.706  0.132  0.878  1.0
  O  O8  1  0.353  0.452  0.171  1.0
  O  O9  1  0.647  0.548  0.829  1.0
  O  O10  1  0.606  0.647  0.431  1.0
  O  O11  1  0.394  0.353  0.569  1.0
  O  O12  1  0.052  0.214  0.456  1.0
  O  O13  1  0.948  0.786  0.544  1.0
  O  O14  1  0.079  0.280  0.793  1.0
  O  O15  1  0.921  0.720  0.207  1.0
  O  O16  1  0.607  0.044  0.326  1.0
  O  O17  1  0.393  0.956  0.674  1.0
  P  P18  1  0.185  0.687  0.095  1.0
  P  P19  1  0.815  0.313  0.905  1.0
  P  P20  1  0.234  0.198  0.614  1.0
  P  P21  1  0.766  0.802  0.386  1.0
[/CIF]
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