The crystal structure described by MgNb2(PO5)2 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form MgO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra. Nb(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Nb(1) 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 Nb(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one Nb(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgNb2(PO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.434
_cell_length_b   6.696
_cell_length_c   6.696
_cell_angle_alpha   87.786
_cell_angle_beta   91.984
_cell_angle_gamma   91.984
_symmetry_Int_Tables_number   1
_cell_volume   198.442
_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
  Mg  Mg0  1  0.000  0.000  0.000  1.0
  Nb  Nb1  1  0.399  0.750  0.750  1.0
  Nb  Nb2  1  0.601  0.250  0.250  1.0
  P  P3  1  0.500  0.748  0.252  1.0
  P  P4  1  0.500  0.252  0.748  1.0
  O  O5  1  0.680  0.557  0.244  1.0
  O  O6  1  0.720  0.935  0.236  1.0
  O  O7  1  0.202  0.206  0.206  1.0
  O  O8  1  0.798  0.794  0.794  1.0
  O  O9  1  0.720  0.236  0.935  1.0
  O  O10  1  0.680  0.244  0.557  1.0
  O  O11  1  0.320  0.756  0.443  1.0
  O  O12  1  0.280  0.065  0.764  1.0
  O  O13  1  0.320  0.443  0.756  1.0
  O  O14  1  0.280  0.764  0.065  1.0
[/CIF]
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The crystal structure described by MgNb2(PO5)2 crystallizes in the monoclinic C2/m space group. Mg(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form MgO6 octahedra that share corners with four equivalent P(1)O4 tetrahedra. Nb(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Nb(1) 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 Nb(1), and one P(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Mg(1) and one Nb(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgNb2(PO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.434
_cell_length_b   6.696
_cell_length_c   6.696
_cell_angle_alpha   87.786
_cell_angle_beta   91.984
_cell_angle_gamma   91.984
_symmetry_Int_Tables_number   1
_cell_volume   198.442
_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
  Mg  Mg0  1  0.000  0.000  0.000  1.0
  Nb  Nb1  1  0.399  0.750  0.750  1.0
  Nb  Nb2  1  0.601  0.250  0.250  1.0
  P  P3  1  0.500  0.748  0.252  1.0
  P  P4  1  0.500  0.252  0.748  1.0
  O  O5  1  0.680  0.557  0.244  1.0
  O  O6  1  0.720  0.935  0.236  1.0
  O  O7  1  0.202  0.206  0.206  1.0
  O  O8  1  0.798  0.794  0.794  1.0
  O  O9  1  0.720  0.236  0.935  1.0
  O  O10  1  0.680  0.244  0.557  1.0
  O  O11  1  0.320  0.756  0.443  1.0
  O  O12  1  0.280  0.065  0.764  1.0
  O  O13  1  0.320  0.443  0.756  1.0
  O  O14  1  0.280  0.764  0.065  1.0
[/CIF]
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