The crystal structure described by MgCr(GeO3)2 crystallizes in the monoclinic P2_1/c space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form MgO6 octahedra that share corners with two equivalent Ge(2)O4 tetrahedra, corners with four equivalent Ge(1)O4 tetrahedra, edges with three equivalent Cr(1)O6 octahedra, and  an edgeedge with one Ge(2)O4 tetrahedra. Cr(1) is bonded to one O(3), one O(4), two equivalent O(5), and two equivalent O(6) atoms to form CrO6 octahedra that share corners with three equivalent Ge(1)O4 tetrahedra, corners with three equivalent Ge(2)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with three equivalent Mg(1)O6 octahedra. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form GeO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-65°. In the second Ge site, Ge(2) is bonded to one O(3), one O(6), and two equivalent O(1) atoms to form GeO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra, corners with two equivalent Ge(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-64°. There are six inequivalent O sites. In the first O site, O(5) is bonded to one Mg(1), two equivalent Cr(1), and one Ge(1) atom to form distorted corner-sharing OMgCr2Ge trigonal pyramids. In the second O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), two equivalent Cr(1), and one Ge(2) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1) and two equivalent Ge(2) atoms. In the fourth O site, O(2) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent Ge(1) atoms. In the fifth O site, O(3) is bonded in a T-shaped geometry to one Mg(1), one Cr(1), and one Ge(2) atom. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one Cr(1), and one Ge(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgCr(GeO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.368
_cell_length_b   5.436
_cell_length_c   9.868
_cell_angle_alpha   77.042
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   489.745
_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  0.488  0.554  0.242  1.0
  Mg  Mg1  1  0.988  0.946  0.758  1.0
  Mg  Mg2  1  0.512  0.446  0.758  1.0
  Mg  Mg3  1  0.012  0.054  0.242  1.0
  Cr  Cr4  1  0.654  0.046  0.245  1.0
  Cr  Cr5  1  0.154  0.454  0.755  1.0
  Cr  Cr6  1  0.346  0.954  0.755  1.0
  Cr  Cr7  1  0.846  0.546  0.245  1.0
  Ge  Ge8  1  0.335  0.171  0.055  1.0
  Ge  Ge9  1  0.835  0.329  0.945  1.0
  Ge  Ge10  1  0.665  0.829  0.945  1.0
  Ge  Ge11  1  0.165  0.671  0.055  1.0
  Ge  Ge12  1  0.345  0.759  0.456  1.0
  Ge  Ge13  1  0.845  0.741  0.544  1.0
  Ge  Ge14  1  0.655  0.241  0.544  1.0
  Ge  Ge15  1  0.155  0.259  0.456  1.0
  O  O16  1  0.290  0.489  0.388  1.0
  O  O17  1  0.790  0.011  0.612  1.0
  O  O18  1  0.710  0.511  0.612  1.0
  O  O19  1  0.210  0.989  0.388  1.0
  O  O20  1  0.324  0.826  0.107  1.0
  O  O21  1  0.824  0.674  0.893  1.0
  O  O22  1  0.676  0.174  0.893  1.0
  O  O23  1  0.176  0.326  0.107  1.0
  O  O24  1  0.993  0.304  0.369  1.0
  O  O25  1  0.493  0.196  0.631  1.0
  O  O26  1  0.007  0.696  0.631  1.0
  O  O27  1  0.507  0.804  0.369  1.0
  O  O28  1  0.025  0.785  0.135  1.0
  O  O29  1  0.525  0.715  0.865  1.0
  O  O30  1  0.975  0.215  0.865  1.0
  O  O31  1  0.475  0.285  0.135  1.0
  O  O32  1  0.338  0.240  0.870  1.0
  O  O33  1  0.838  0.260  0.130  1.0
  O  O34  1  0.662  0.760  0.130  1.0
  O  O35  1  0.162  0.740  0.870  1.0
  O  O36  1  0.353  0.684  0.638  1.0
  O  O37  1  0.853  0.816  0.362  1.0
  O  O38  1  0.647  0.316  0.362  1.0
  O  O39  1  0.147  0.184  0.638  1.0
[/CIF]
.
The crystal structure described by MgCr(GeO3)2 crystallizes in the monoclinic P2_1/c space group. Mg(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form MgO6 octahedra that share corners with two equivalent Ge(2)O4 tetrahedra, corners with four equivalent Ge(1)O4 tetrahedra, edges with three equivalent Cr(1)O6 octahedra, and  an edgeedge with one Ge(2)O4 tetrahedra. Cr(1) is bonded to one O(3), one O(4), two equivalent O(5), and two equivalent O(6) atoms to form CrO6 octahedra that share corners with three equivalent Ge(1)O4 tetrahedra, corners with three equivalent Ge(2)O4 tetrahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with three equivalent Mg(1)O6 octahedra. There are two inequivalent Ge sites. In the first Ge site, Ge(1) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form GeO4 tetrahedra that share corners with three equivalent Cr(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, and corners with two equivalent Ge(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-65°. In the second Ge site, Ge(2) is bonded to one O(3), one O(6), and two equivalent O(1) atoms to form GeO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with three equivalent Cr(1)O6 octahedra, corners with two equivalent Ge(2)O4 tetrahedra, and  an edgeedge with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-64°. There are six inequivalent O sites. In the first O site, O(5) is bonded to one Mg(1), two equivalent Cr(1), and one Ge(1) atom to form distorted corner-sharing OMgCr2Ge trigonal pyramids. In the second O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), two equivalent Cr(1), and one Ge(2) atom. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Mg(1) and two equivalent Ge(2) atoms. In the fourth O site, O(2) is bonded in a trigonal planar geometry to one Mg(1) and two equivalent Ge(1) atoms. In the fifth O site, O(3) is bonded in a T-shaped geometry to one Mg(1), one Cr(1), and one Ge(2) atom. In the sixth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one Cr(1), and one Ge(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_MgCr(GeO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.368
_cell_length_b   5.436
_cell_length_c   9.868
_cell_angle_alpha   77.042
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   489.745
_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  0.488  0.554  0.242  1.0
  Mg  Mg1  1  0.988  0.946  0.758  1.0
  Mg  Mg2  1  0.512  0.446  0.758  1.0
  Mg  Mg3  1  0.012  0.054  0.242  1.0
  Cr  Cr4  1  0.654  0.046  0.245  1.0
  Cr  Cr5  1  0.154  0.454  0.755  1.0
  Cr  Cr6  1  0.346  0.954  0.755  1.0
  Cr  Cr7  1  0.846  0.546  0.245  1.0
  Ge  Ge8  1  0.335  0.171  0.055  1.0
  Ge  Ge9  1  0.835  0.329  0.945  1.0
  Ge  Ge10  1  0.665  0.829  0.945  1.0
  Ge  Ge11  1  0.165  0.671  0.055  1.0
  Ge  Ge12  1  0.345  0.759  0.456  1.0
  Ge  Ge13  1  0.845  0.741  0.544  1.0
  Ge  Ge14  1  0.655  0.241  0.544  1.0
  Ge  Ge15  1  0.155  0.259  0.456  1.0
  O  O16  1  0.290  0.489  0.388  1.0
  O  O17  1  0.790  0.011  0.612  1.0
  O  O18  1  0.710  0.511  0.612  1.0
  O  O19  1  0.210  0.989  0.388  1.0
  O  O20  1  0.324  0.826  0.107  1.0
  O  O21  1  0.824  0.674  0.893  1.0
  O  O22  1  0.676  0.174  0.893  1.0
  O  O23  1  0.176  0.326  0.107  1.0
  O  O24  1  0.993  0.304  0.369  1.0
  O  O25  1  0.493  0.196  0.631  1.0
  O  O26  1  0.007  0.696  0.631  1.0
  O  O27  1  0.507  0.804  0.369  1.0
  O  O28  1  0.025  0.785  0.135  1.0
  O  O29  1  0.525  0.715  0.865  1.0
  O  O30  1  0.975  0.215  0.865  1.0
  O  O31  1  0.475  0.285  0.135  1.0
  O  O32  1  0.338  0.240  0.870  1.0
  O  O33  1  0.838  0.260  0.130  1.0
  O  O34  1  0.662  0.760  0.130  1.0
  O  O35  1  0.162  0.740  0.870  1.0
  O  O36  1  0.353  0.684  0.638  1.0
  O  O37  1  0.853  0.816  0.362  1.0
  O  O38  1  0.647  0.316  0.362  1.0
  O  O39  1  0.147  0.184  0.638  1.0
[/CIF]
.