The compound described by MgCr3(SO4)6 crystallizes in the trigonal R3 space group. Mg(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form MgO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent O(1) and three equivalent O(6) atoms to form CrO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. In the second Cr site, Cr(2) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form CrO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. In the third Cr site, Cr(3) is bonded to three equivalent O(3) and three equivalent O(5) atoms to form CrO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(2), one O(3), one O(6), and one O(8) atom to form SO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  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 28-42°. In the second S site, S(2) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form SO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  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 30-43°. There are eight inequivalent O sites. In the first O site, O(2) is bonded in a bent 150 degrees geometry to one Mg(1) and one S(1) atom. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(3) and one S(1) atom. In the third O site, O(4) is bonded in a bent 150 degrees geometry to one Mg(1) and one S(2) atom. In the fourth O site, O(5) is bonded in a bent 150 degrees geometry to one Cr(3) and one S(2) atom. In the fifth O site, O(6) is bonded in a bent 150 degrees geometry to one Cr(1) and one S(1) atom. In the sixth O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Cr(2) and one S(2) atom. In the seventh O site, O(8) is bonded in a bent 150 degrees geometry to one Cr(2) and one S(1) atom. In the eighth O site, O(1) is bonded in a bent 150 degrees geometry to one Cr(1) and one S(2) atom. is represented by the CIF file [CIF]
data_MgCr3(SO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.872
_cell_length_b   8.872
_cell_length_c   8.872
_cell_angle_alpha   56.019
_cell_angle_beta   56.019
_cell_angle_gamma   56.019
_symmetry_Int_Tables_number   1
_cell_volume   448.295
_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  0.853  0.853  0.853  1.0
  Cr  Cr1  1  0.645  0.645  0.645  1.0
  Cr  Cr2  1  0.356  0.356  0.356  1.0
  Cr  Cr3  1  0.150  0.150  0.150  1.0
  S  S4  1  0.962  0.255  0.533  1.0
  S  S5  1  0.461  0.043  0.747  1.0
  S  S6  1  0.747  0.461  0.043  1.0
  S  S7  1  0.255  0.533  0.962  1.0
  S  S8  1  0.533  0.962  0.255  1.0
  S  S9  1  0.043  0.747  0.461  1.0
  O  O10  1  0.703  0.482  0.892  1.0
  O  O11  1  0.892  0.703  0.482  1.0
  O  O12  1  0.987  0.054  0.666  1.0
  O  O13  1  0.978  0.287  0.340  1.0
  O  O14  1  0.647  0.027  0.719  1.0
  O  O15  1  0.952  0.323  0.018  1.0
  O  O16  1  0.482  0.892  0.703  1.0
  O  O17  1  0.765  0.389  0.613  1.0
  O  O18  1  0.323  0.018  0.952  1.0
  O  O19  1  0.619  0.370  0.239  1.0
  O  O20  1  0.370  0.239  0.619  1.0
  O  O21  1  0.719  0.647  0.027  1.0
  O  O22  1  0.287  0.340  0.978  1.0
  O  O23  1  0.613  0.765  0.389  1.0
  O  O24  1  0.389  0.613  0.765  1.0
  O  O25  1  0.666  0.987  0.054  1.0
  O  O26  1  0.239  0.619  0.370  1.0
  O  O27  1  0.505  0.108  0.311  1.0
  O  O28  1  0.054  0.666  0.987  1.0
  O  O29  1  0.340  0.978  0.287  1.0
  O  O30  1  0.027  0.719  0.647  1.0
  O  O31  1  0.018  0.952  0.323  1.0
  O  O32  1  0.108  0.311  0.505  1.0
  O  O33  1  0.311  0.505  0.108  1.0
[/CIF]
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The compound described by MgCr3(SO4)6 crystallizes in the trigonal R3 space group. Mg(1) is bonded to three equivalent O(2) and three equivalent O(4) atoms to form MgO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. There are three inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to three equivalent O(1) and three equivalent O(6) atoms to form CrO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. In the second Cr site, Cr(2) is bonded to three equivalent O(7) and three equivalent O(8) atoms to form CrO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. In the third Cr site, Cr(3) is bonded to three equivalent O(3) and three equivalent O(5) atoms to form CrO6 octahedra that share corners with three equivalent S(1)O4 tetrahedra and corners with three equivalent S(2)O4 tetrahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(2), one O(3), one O(6), and one O(8) atom to form SO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  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 28-42°. In the second S site, S(2) is bonded to one O(1), one O(4), one O(5), and one O(7) atom to form SO4 tetrahedra that share  a cornercorner with one Mg(1)O6 octahedra,  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 30-43°. There are eight inequivalent O sites. In the first O site, O(2) is bonded in a bent 150 degrees geometry to one Mg(1) and one S(1) atom. In the second O site, O(3) is bonded in a bent 150 degrees geometry to one Cr(3) and one S(1) atom. In the third O site, O(4) is bonded in a bent 150 degrees geometry to one Mg(1) and one S(2) atom. In the fourth O site, O(5) is bonded in a bent 150 degrees geometry to one Cr(3) and one S(2) atom. In the fifth O site, O(6) is bonded in a bent 150 degrees geometry to one Cr(1) and one S(1) atom. In the sixth O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Cr(2) and one S(2) atom. In the seventh O site, O(8) is bonded in a bent 150 degrees geometry to one Cr(2) and one S(1) atom. In the eighth O site, O(1) is bonded in a bent 150 degrees geometry to one Cr(1) and one S(2) atom. is represented by the CIF file [CIF]
data_MgCr3(SO4)6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.872
_cell_length_b   8.872
_cell_length_c   8.872
_cell_angle_alpha   56.019
_cell_angle_beta   56.019
_cell_angle_gamma   56.019
_symmetry_Int_Tables_number   1
_cell_volume   448.295
_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  0.853  0.853  0.853  1.0
  Cr  Cr1  1  0.645  0.645  0.645  1.0
  Cr  Cr2  1  0.356  0.356  0.356  1.0
  Cr  Cr3  1  0.150  0.150  0.150  1.0
  S  S4  1  0.962  0.255  0.533  1.0
  S  S5  1  0.461  0.043  0.747  1.0
  S  S6  1  0.747  0.461  0.043  1.0
  S  S7  1  0.255  0.533  0.962  1.0
  S  S8  1  0.533  0.962  0.255  1.0
  S  S9  1  0.043  0.747  0.461  1.0
  O  O10  1  0.703  0.482  0.892  1.0
  O  O11  1  0.892  0.703  0.482  1.0
  O  O12  1  0.987  0.054  0.666  1.0
  O  O13  1  0.978  0.287  0.340  1.0
  O  O14  1  0.647  0.027  0.719  1.0
  O  O15  1  0.952  0.323  0.018  1.0
  O  O16  1  0.482  0.892  0.703  1.0
  O  O17  1  0.765  0.389  0.613  1.0
  O  O18  1  0.323  0.018  0.952  1.0
  O  O19  1  0.619  0.370  0.239  1.0
  O  O20  1  0.370  0.239  0.619  1.0
  O  O21  1  0.719  0.647  0.027  1.0
  O  O22  1  0.287  0.340  0.978  1.0
  O  O23  1  0.613  0.765  0.389  1.0
  O  O24  1  0.389  0.613  0.765  1.0
  O  O25  1  0.666  0.987  0.054  1.0
  O  O26  1  0.239  0.619  0.370  1.0
  O  O27  1  0.505  0.108  0.311  1.0
  O  O28  1  0.054  0.666  0.987  1.0
  O  O29  1  0.340  0.978  0.287  1.0
  O  O30  1  0.027  0.719  0.647  1.0
  O  O31  1  0.018  0.952  0.323  1.0
  O  O32  1  0.108  0.311  0.505  1.0
  O  O33  1  0.311  0.505  0.108  1.0
[/CIF]
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