The compound described by MgCrP2O7 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted MgO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra and edges with two equivalent P(1)O4 tetrahedra. Cr(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. 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  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  an edgeedge with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 56°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Cr(1), and one P(1) atom. In the second O site, O(2) is bonded in an L-shaped geometry to one Mg(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Mg(1), one Cr(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to two equivalent P(1) atoms. is represented by the CIF file [CIF]
data_MgCrP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.521
_cell_length_b   5.521
_cell_length_c   5.764
_cell_angle_alpha   71.053
_cell_angle_beta   108.949
_cell_angle_gamma   83.693
_symmetry_Int_Tables_number   1
_cell_volume   152.519
_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  0.125  0.125  0.500  1.0
  Cr  Cr1  1  0.129  0.129  0.000  1.0
  P  P2  1  0.632  0.301  0.424  1.0
  P  P3  1  0.301  0.632  0.576  1.0
  O  O4  1  0.220  0.373  0.692  1.0
  O  O5  1  0.774  0.370  0.235  1.0
  O  O6  1  0.836  0.088  0.691  1.0
  O  O7  1  0.370  0.774  0.765  1.0
  O  O8  1  0.548  0.548  0.500  1.0
  O  O9  1  0.088  0.836  0.309  1.0
  O  O10  1  0.373  0.220  0.308  1.0
[/CIF]
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The compound described by MgCrP2O7 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted MgO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra and edges with two equivalent P(1)O4 tetrahedra. Cr(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. 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  a cornercorner with one Mg(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  an edgeedge with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles are 56°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1), one Cr(1), and one P(1) atom. In the second O site, O(2) is bonded in an L-shaped geometry to one Mg(1) and one P(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Mg(1), one Cr(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to two equivalent P(1) atoms. is represented by the CIF file [CIF]
data_MgCrP2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.521
_cell_length_b   5.521
_cell_length_c   5.764
_cell_angle_alpha   71.053
_cell_angle_beta   108.949
_cell_angle_gamma   83.693
_symmetry_Int_Tables_number   1
_cell_volume   152.519
_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  0.125  0.125  0.500  1.0
  Cr  Cr1  1  0.129  0.129  0.000  1.0
  P  P2  1  0.632  0.301  0.424  1.0
  P  P3  1  0.301  0.632  0.576  1.0
  O  O4  1  0.220  0.373  0.692  1.0
  O  O5  1  0.774  0.370  0.235  1.0
  O  O6  1  0.836  0.088  0.691  1.0
  O  O7  1  0.370  0.774  0.765  1.0
  O  O8  1  0.548  0.548  0.500  1.0
  O  O9  1  0.088  0.836  0.309  1.0
  O  O10  1  0.373  0.220  0.308  1.0
[/CIF]
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