The crystal structure described by MgCr3(SO4)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 6-coordinate geometry to one O(13), one O(24), one O(3), one O(4), one O(7), and one O(9) atom. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(11), one O(12), one O(15), one O(20), one O(3), and one O(8) atom to form CrO6 octahedra that share  a cornercorner with one S(1)O4 tetrahedra,  a cornercorner with one S(2)O4 tetrahedra,  a cornercorner with one S(3)O4 tetrahedra,  a cornercorner with one S(4)O4 tetrahedra,  a cornercorner with one S(5)O4 tetrahedra, and  a cornercorner with one S(6)O4 tetrahedra. In the second Cr site, Cr(2) is bonded to one O(16), one O(18), one O(19), one O(21), one O(23), and one O(24) atom to form CrO6 octahedra that share  a cornercorner with one S(1)O4 tetrahedra,  a cornercorner with one S(2)O4 tetrahedra,  a cornercorner with one S(3)O4 tetrahedra,  a cornercorner with one S(4)O4 tetrahedra,  a cornercorner with one S(5)O4 tetrahedra, and  a cornercorner with one S(6)O4 tetrahedra. In the third Cr site, Cr(3) is bonded to one O(10), one O(13), one O(14), one O(17), one O(22), and one O(5) atom to form CrO6 octahedra that share  a cornercorner with one S(1)O4 tetrahedra,  a cornercorner with one S(2)O4 tetrahedra,  a cornercorner with one S(3)O4 tetrahedra,  a cornercorner with one S(4)O4 tetrahedra,  a cornercorner with one S(5)O4 tetrahedra, and  a cornercorner with one S(6)O4 tetrahedra. There are six inequivalent S sites. In the first S site, S(1) is bonded to one O(24), one O(3), one O(5), and one O(6) atom to form SO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, and  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-50°. In the second S site, S(2) is bonded to one O(13), one O(21), one O(7), and one O(8) atom to form SO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, and  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-44°. In the third S site, S(3) is bonded to one O(14), one O(15), one O(23), and one O(9) atom to form SO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, and  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-44°. In the fourth S site, S(4) is bonded to one O(10), one O(11), one O(16), and one O(2) atom to form SO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, and  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-45°. In the fifth S site, S(5) is bonded to one O(12), one O(17), one O(18), and one O(4) atom to form SO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, and  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-47°. In the sixth S site, S(6) is bonded to one O(1), one O(19), one O(20), and one O(22) atom to form SO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, and  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-47°. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one S(6) atom. In the second O site, O(2) is bonded in a single-bond geometry to one S(4) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mg(1), one Cr(1), and one S(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Mg(1) and one S(5) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Cr(3) and one S(1) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one S(1) atom. In the seventh O site, O(7) is bonded in an L-shaped geometry to one Mg(1) and one S(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Cr(1) and one S(2) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Mg(1) and one S(3) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Cr(3) and one S(4) atom. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one S(4) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Cr(1) and one S(5) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Mg(1), one Cr(3), and one S(2) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Cr(3) and one S(3) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one S(3) atom. In the sixteenth O site, O(16) is bonded in a distorted bent 150 degrees geometry to one Cr(2) and one S(4) atom. In the seventeenth O site, O(17) is bonded in a bent 150 degrees geometry to one Cr(3) and one S(5) atom. In the eighteenth O site, O(18) is bonded in a distorted bent 120 degrees geometry to one Cr(2) and one S(5) atom. In the nineteenth O site, O(19) is bonded in a distorted bent 150 degrees geometry to one Cr(2) and one S(6) atom. In the twentieth O site, O(20) is bonded in a distorted bent 120 degrees geometry to one Cr(1) and one S(6) atom. In the twenty-first O site, O(21) is bonded in a bent 150 degrees geometry to one Cr(2) and one S(2) atom. In the twenty-second O site, O(22) is bonded in a bent 150 degrees geometry to one Cr(3) and one S(6) atom. In the twenty-third O site, O(23) is bonded in a bent 150 degrees geometry to one Cr(2) and one S(3) atom. In the twenty-fourth O site, O(24) is bonded in a distorted bent 150 degrees geometry to one Mg(1), one Cr(2), and one S(1) atom. is represented by the CIF card [CIF]
data_MgCr3(SO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.895
_cell_length_b   9.145
_cell_length_c   8.920
_cell_angle_alpha   55.781
_cell_angle_beta   55.694
_cell_angle_gamma   55.106
_symmetry_Int_Tables_number   1
_cell_volume   459.701
_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  0.664  0.123  0.398  1.0
  Cr  Cr1  1  0.152  0.161  0.157  1.0
  Cr  Cr2  1  0.643  0.637  0.651  1.0
  Cr  Cr3  1  0.856  0.843  0.843  1.0
  S  S4  1  0.031  0.776  0.448  1.0
  S  S5  1  0.450  0.019  0.773  1.0
  S  S6  1  0.769  0.462  0.028  1.0
  S  S7  1  0.257  0.531  0.962  1.0
  S  S8  1  0.550  0.943  0.256  1.0
  S  S9  1  0.955  0.250  0.544  1.0
  O  O10  1  0.116  0.277  0.515  1.0
  O  O11  1  0.294  0.501  0.118  1.0
  O  O12  1  0.975  0.995  0.334  1.0
  O  O13  1  0.558  0.078  0.290  1.0
  O  O14  1  0.035  0.730  0.636  1.0
  O  O15  1  0.213  0.669  0.338  1.0
  O  O16  1  0.387  0.199  0.622  1.0
  O  O17  1  0.329  0.012  0.974  1.0
  O  O18  1  0.645  0.382  0.226  1.0
  O  O19  1  0.050  0.665  0.978  1.0
  O  O20  1  0.290  0.343  0.977  1.0
  O  O21  1  0.343  0.989  0.294  1.0
  O  O22  1  0.658  0.999  0.715  1.0
  O  O23  1  0.730  0.654  0.006  1.0
  O  O24  1  0.980  0.335  0.995  1.0
  O  O25  1  0.388  0.611  0.764  1.0
  O  O26  1  0.673  0.958  0.051  1.0
  O  O27  1  0.621  0.745  0.391  1.0
  O  O28  1  0.757  0.383  0.628  1.0
  O  O29  1  0.964  0.290  0.349  1.0
  O  O30  1  0.465  0.858  0.755  1.0
  O  O31  1  0.966  0.050  0.673  1.0
  O  O32  1  0.723  0.477  0.884  1.0
  O  O33  1  0.851  0.757  0.488  1.0
[/CIF]
.
The crystal structure described by MgCr3(SO4)6 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 6-coordinate geometry to one O(13), one O(24), one O(3), one O(4), one O(7), and one O(9) atom. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(11), one O(12), one O(15), one O(20), one O(3), and one O(8) atom to form CrO6 octahedra that share  a cornercorner with one S(1)O4 tetrahedra,  a cornercorner with one S(2)O4 tetrahedra,  a cornercorner with one S(3)O4 tetrahedra,  a cornercorner with one S(4)O4 tetrahedra,  a cornercorner with one S(5)O4 tetrahedra, and  a cornercorner with one S(6)O4 tetrahedra. In the second Cr site, Cr(2) is bonded to one O(16), one O(18), one O(19), one O(21), one O(23), and one O(24) atom to form CrO6 octahedra that share  a cornercorner with one S(1)O4 tetrahedra,  a cornercorner with one S(2)O4 tetrahedra,  a cornercorner with one S(3)O4 tetrahedra,  a cornercorner with one S(4)O4 tetrahedra,  a cornercorner with one S(5)O4 tetrahedra, and  a cornercorner with one S(6)O4 tetrahedra. In the third Cr site, Cr(3) is bonded to one O(10), one O(13), one O(14), one O(17), one O(22), and one O(5) atom to form CrO6 octahedra that share  a cornercorner with one S(1)O4 tetrahedra,  a cornercorner with one S(2)O4 tetrahedra,  a cornercorner with one S(3)O4 tetrahedra,  a cornercorner with one S(4)O4 tetrahedra,  a cornercorner with one S(5)O4 tetrahedra, and  a cornercorner with one S(6)O4 tetrahedra. There are six inequivalent S sites. In the first S site, S(1) is bonded to one O(24), one O(3), one O(5), and one O(6) atom to form SO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, and  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-50°. In the second S site, S(2) is bonded to one O(13), one O(21), one O(7), and one O(8) atom to form SO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, and  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-44°. In the third S site, S(3) is bonded to one O(14), one O(15), one O(23), and one O(9) atom to form SO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, and  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-44°. In the fourth S site, S(4) is bonded to one O(10), one O(11), one O(16), and one O(2) atom to form SO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, and  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-45°. In the fifth S site, S(5) is bonded to one O(12), one O(17), one O(18), and one O(4) atom to form SO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, and  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-47°. In the sixth S site, S(6) is bonded to one O(1), one O(19), one O(20), and one O(22) atom to form SO4 tetrahedra that share  a cornercorner with one Cr(1)O6 octahedra,  a cornercorner with one Cr(2)O6 octahedra, and  a cornercorner with one Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-47°. There are twenty-four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one S(6) atom. In the second O site, O(2) is bonded in a single-bond geometry to one S(4) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mg(1), one Cr(1), and one S(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Mg(1) and one S(5) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Cr(3) and one S(1) atom. In the sixth O site, O(6) is bonded in a single-bond geometry to one S(1) atom. In the seventh O site, O(7) is bonded in an L-shaped geometry to one Mg(1) and one S(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Cr(1) and one S(2) atom. In the ninth O site, O(9) is bonded in a bent 120 degrees geometry to one Mg(1) and one S(3) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Cr(3) and one S(4) atom. In the eleventh O site, O(11) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one S(4) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Cr(1) and one S(5) atom. In the thirteenth O site, O(13) is bonded in a 3-coordinate geometry to one Mg(1), one Cr(3), and one S(2) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Cr(3) and one S(3) atom. In the fifteenth O site, O(15) is bonded in a distorted bent 150 degrees geometry to one Cr(1) and one S(3) atom. In the sixteenth O site, O(16) is bonded in a distorted bent 150 degrees geometry to one Cr(2) and one S(4) atom. In the seventeenth O site, O(17) is bonded in a bent 150 degrees geometry to one Cr(3) and one S(5) atom. In the eighteenth O site, O(18) is bonded in a distorted bent 120 degrees geometry to one Cr(2) and one S(5) atom. In the nineteenth O site, O(19) is bonded in a distorted bent 150 degrees geometry to one Cr(2) and one S(6) atom. In the twentieth O site, O(20) is bonded in a distorted bent 120 degrees geometry to one Cr(1) and one S(6) atom. In the twenty-first O site, O(21) is bonded in a bent 150 degrees geometry to one Cr(2) and one S(2) atom. In the twenty-second O site, O(22) is bonded in a bent 150 degrees geometry to one Cr(3) and one S(6) atom. In the twenty-third O site, O(23) is bonded in a bent 150 degrees geometry to one Cr(2) and one S(3) atom. In the twenty-fourth O site, O(24) is bonded in a distorted bent 150 degrees geometry to one Mg(1), one Cr(2), and one S(1) atom. is represented by the CIF card [CIF]
data_MgCr3(SO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.895
_cell_length_b   9.145
_cell_length_c   8.920
_cell_angle_alpha   55.781
_cell_angle_beta   55.694
_cell_angle_gamma   55.106
_symmetry_Int_Tables_number   1
_cell_volume   459.701
_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  0.664  0.123  0.398  1.0
  Cr  Cr1  1  0.152  0.161  0.157  1.0
  Cr  Cr2  1  0.643  0.637  0.651  1.0
  Cr  Cr3  1  0.856  0.843  0.843  1.0
  S  S4  1  0.031  0.776  0.448  1.0
  S  S5  1  0.450  0.019  0.773  1.0
  S  S6  1  0.769  0.462  0.028  1.0
  S  S7  1  0.257  0.531  0.962  1.0
  S  S8  1  0.550  0.943  0.256  1.0
  S  S9  1  0.955  0.250  0.544  1.0
  O  O10  1  0.116  0.277  0.515  1.0
  O  O11  1  0.294  0.501  0.118  1.0
  O  O12  1  0.975  0.995  0.334  1.0
  O  O13  1  0.558  0.078  0.290  1.0
  O  O14  1  0.035  0.730  0.636  1.0
  O  O15  1  0.213  0.669  0.338  1.0
  O  O16  1  0.387  0.199  0.622  1.0
  O  O17  1  0.329  0.012  0.974  1.0
  O  O18  1  0.645  0.382  0.226  1.0
  O  O19  1  0.050  0.665  0.978  1.0
  O  O20  1  0.290  0.343  0.977  1.0
  O  O21  1  0.343  0.989  0.294  1.0
  O  O22  1  0.658  0.999  0.715  1.0
  O  O23  1  0.730  0.654  0.006  1.0
  O  O24  1  0.980  0.335  0.995  1.0
  O  O25  1  0.388  0.611  0.764  1.0
  O  O26  1  0.673  0.958  0.051  1.0
  O  O27  1  0.621  0.745  0.391  1.0
  O  O28  1  0.757  0.383  0.628  1.0
  O  O29  1  0.964  0.290  0.349  1.0
  O  O30  1  0.465  0.858  0.755  1.0
  O  O31  1  0.966  0.050  0.673  1.0
  O  O32  1  0.723  0.477  0.884  1.0
  O  O33  1  0.851  0.757  0.488  1.0
[/CIF]
.