The structure described by MgCr2(PO5)2 crystallizes in the monoclinic C2 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to two equivalent O(1,4); two equivalent O(10); two equivalent O(5,8); and two equivalent O(6) atoms. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to two equivalent O(1,4); two equivalent O(3); two equivalent O(5,8); and two equivalent O(9) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1,4); one O(2); one O(3); one O(5,8); one O(6); and one O(7) atom to form CrO6 octahedra that share corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. In the second Cr site, Cr(2) is bonded to one O(1,4); one O(10); one O(2); one O(5,8); one O(7); and one O(9) atom to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1,4); one O(10); one O(5,8); and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra and corners with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-62°. In the second P site, P(2) is bonded to one O(1,4); one O(3); one O(5,8); and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra and corners with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-62°. There are eight inequivalent O sites. In the first O site, O(9) is bonded in a trigonal planar geometry to one Mg(2), one Cr(2), and one P(2) atom. In the second O site, O(10) is bonded in a trigonal planar geometry to one Mg(1), one Cr(2), and one P(1) atom. In the third O site, O(1,4) is bonded in a 2-coordinate geometry to one Mg(2), one Cr(1), and one P(1) atom. In the fourth O site, O(2) is bonded in a bent 120 degrees geometry to one Cr(1) and one Cr(2) atom. In the fifth O site, O(3) is bonded in a trigonal planar geometry to one Mg(2), one Cr(1), and one P(2) atom. In the sixth O site, O(5,8) is bonded in a 2-coordinate geometry to one Mg(2), one Cr(2), and one P(1) atom. In the seventh O site, O(6) is bonded in a trigonal planar geometry to one Mg(1), one Cr(1), and one P(1) atom. In the eighth O site, O(7) is bonded in a bent 120 degrees geometry to one Cr(1) and one Cr(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgCr2(PO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.687
_cell_length_b   6.688
_cell_length_c   8.705
_cell_angle_alpha   102.675
_cell_angle_beta   102.713
_cell_angle_gamma   115.353
_symmetry_Int_Tables_number   1
_cell_volume   320.726
_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  0.493  0.993  0.500  1.0
  Mg  Mg1  1  0.243  0.243  1.000  1.0
  Cr  Cr2  1  0.871  0.620  0.251  1.0
  Cr  Cr3  1  0.369  0.620  0.750  1.0
  Cr  Cr4  1  0.870  0.119  0.250  1.0
  Cr  Cr5  1  0.870  0.621  0.750  1.0
  P  P6  1  0.037  0.038  0.585  1.0
  P  P7  1  0.702  0.203  0.915  1.0
  P  P8  1  0.453  0.452  0.415  1.0
  P  P9  1  0.288  0.787  0.085  1.0
  O  O10  1  0.578  0.554  0.299  1.0
  O  O11  1  0.664  0.667  0.841  1.0
  O  O12  1  0.311  0.588  0.970  1.0
  O  O13  1  0.804  0.328  0.799  1.0
  O  O14  1  0.213  0.235  0.296  1.0
  O  O15  1  0.427  0.649  0.529  1.0
  O  O16  1  0.075  0.576  0.659  1.0
  O  O17  1  0.826  0.824  0.159  1.0
  O  O18  1  0.917  0.415  0.341  1.0
  O  O19  1  0.167  0.689  0.204  1.0
  O  O20  1  0.255  0.279  0.701  1.0
  O  O21  1  0.485  0.963  0.796  1.0
  O  O22  1  0.939  0.918  0.704  1.0
  O  O23  1  0.148  0.870  0.971  1.0
  O  O24  1  0.120  0.898  0.471  1.0
  O  O25  1  0.899  0.177  0.029  1.0
  O  O26  1  0.838  0.061  0.470  1.0
  O  O27  1  0.619  0.341  0.030  1.0
  O  O28  1  0.529  0.004  0.201  1.0
  O  O29  1  0.591  0.369  0.530  1.0
[/CIF]
.
The structure described by MgCr2(PO5)2 crystallizes in the monoclinic C2 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 8-coordinate geometry to two equivalent O(1,4); two equivalent O(10); two equivalent O(5,8); and two equivalent O(6) atoms. In the second Mg site, Mg(2) is bonded in a 8-coordinate geometry to two equivalent O(1,4); two equivalent O(3); two equivalent O(5,8); and two equivalent O(9) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(1,4); one O(2); one O(3); one O(5,8); one O(6); and one O(7) atom to form CrO6 octahedra that share corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. In the second Cr site, Cr(2) is bonded to one O(1,4); one O(10); one O(2); one O(5,8); one O(7); and one O(9) atom to form CrO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1,4); one O(10); one O(5,8); and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra and corners with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-62°. In the second P site, P(2) is bonded to one O(1,4); one O(3); one O(5,8); and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Cr(1)O6 octahedra and corners with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-62°. There are eight inequivalent O sites. In the first O site, O(9) is bonded in a trigonal planar geometry to one Mg(2), one Cr(2), and one P(2) atom. In the second O site, O(10) is bonded in a trigonal planar geometry to one Mg(1), one Cr(2), and one P(1) atom. In the third O site, O(1,4) is bonded in a 2-coordinate geometry to one Mg(2), one Cr(1), and one P(1) atom. In the fourth O site, O(2) is bonded in a bent 120 degrees geometry to one Cr(1) and one Cr(2) atom. In the fifth O site, O(3) is bonded in a trigonal planar geometry to one Mg(2), one Cr(1), and one P(2) atom. In the sixth O site, O(5,8) is bonded in a 2-coordinate geometry to one Mg(2), one Cr(2), and one P(1) atom. In the seventh O site, O(6) is bonded in a trigonal planar geometry to one Mg(1), one Cr(1), and one P(1) atom. In the eighth O site, O(7) is bonded in a bent 120 degrees geometry to one Cr(1) and one Cr(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgCr2(PO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.687
_cell_length_b   6.688
_cell_length_c   8.705
_cell_angle_alpha   102.675
_cell_angle_beta   102.713
_cell_angle_gamma   115.353
_symmetry_Int_Tables_number   1
_cell_volume   320.726
_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  0.493  0.993  0.500  1.0
  Mg  Mg1  1  0.243  0.243  1.000  1.0
  Cr  Cr2  1  0.871  0.620  0.251  1.0
  Cr  Cr3  1  0.369  0.620  0.750  1.0
  Cr  Cr4  1  0.870  0.119  0.250  1.0
  Cr  Cr5  1  0.870  0.621  0.750  1.0
  P  P6  1  0.037  0.038  0.585  1.0
  P  P7  1  0.702  0.203  0.915  1.0
  P  P8  1  0.453  0.452  0.415  1.0
  P  P9  1  0.288  0.787  0.085  1.0
  O  O10  1  0.578  0.554  0.299  1.0
  O  O11  1  0.664  0.667  0.841  1.0
  O  O12  1  0.311  0.588  0.970  1.0
  O  O13  1  0.804  0.328  0.799  1.0
  O  O14  1  0.213  0.235  0.296  1.0
  O  O15  1  0.427  0.649  0.529  1.0
  O  O16  1  0.075  0.576  0.659  1.0
  O  O17  1  0.826  0.824  0.159  1.0
  O  O18  1  0.917  0.415  0.341  1.0
  O  O19  1  0.167  0.689  0.204  1.0
  O  O20  1  0.255  0.279  0.701  1.0
  O  O21  1  0.485  0.963  0.796  1.0
  O  O22  1  0.939  0.918  0.704  1.0
  O  O23  1  0.148  0.870  0.971  1.0
  O  O24  1  0.120  0.898  0.471  1.0
  O  O25  1  0.899  0.177  0.029  1.0
  O  O26  1  0.838  0.061  0.470  1.0
  O  O27  1  0.619  0.341  0.030  1.0
  O  O28  1  0.529  0.004  0.201  1.0
  O  O29  1  0.591  0.369  0.530  1.0
[/CIF]
.