The material described by KMg6CrO8 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. K(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form KO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent K(1)O6 octahedra, edges with four equivalent Cr(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent K(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with four equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. In the third Mg site, Mg(3) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Mg(3)O6 octahedra, edges with two equivalent K(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. Cr(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form CrO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra, edges with four equivalent K(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are four inequivalent O sites. In the first O site, O(1) is bonded to one K(1), one Mg(1), and four equivalent Mg(3) atoms to form OKMg5 octahedra that share corners with six equivalent O(1)KMg5 octahedra, edges with four equivalent O(3)K2Mg2Cr2 octahedra, edges with four equivalent O(2)Mg5Cr octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the second O site, O(2) is bonded to one Mg(2), four equivalent Mg(3), and one Cr(1) atom to form OMg5Cr octahedra that share corners with six equivalent O(2)Mg5Cr octahedra, edges with four equivalent O(3)K2Mg2Cr2 octahedra, edges with four equivalent O(1)KMg5 octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the third O site, O(3) is bonded to two equivalent K(1), two equivalent Mg(3), and two equivalent Cr(1) atoms to form OK2Mg2Cr2 octahedra that share corners with two equivalent O(4)Mg6 octahedra, corners with four equivalent O(3)K2Mg2Cr2 octahedra, edges with four equivalent O(3)K2Mg2Cr2 octahedra, edges with four equivalent O(1)KMg5 octahedra, and edges with four equivalent O(2)Mg5Cr octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(3)K2Mg2Cr2 octahedra, corners with four equivalent O(4)Mg6 octahedra, edges with four equivalent O(1)KMg5 octahedra, edges with four equivalent O(2)Mg5Cr octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF card [CIF]
data_KMg6CrO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.739
_cell_length_b   4.415
_cell_length_c   4.415
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   170.376
_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
  K  K0  1  0.000  0.000  0.000  1.0
  Mg  Mg1  1  0.500  0.000  0.000  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.254  0.000  0.500  1.0
  Mg  Mg4  1  0.746  0.000  0.500  1.0
  Mg  Mg5  1  0.254  0.500  0.000  1.0
  Mg  Mg6  1  0.746  0.500  0.000  1.0
  Cr  Cr7  1  0.000  0.500  0.500  1.0
  O  O8  1  0.276  0.000  0.000  1.0
  O  O9  1  0.724  0.000  0.000  1.0
  O  O10  1  0.238  0.500  0.500  1.0
  O  O11  1  0.762  0.500  0.500  1.0
  O  O12  1  0.000  0.000  0.500  1.0
  O  O13  1  0.500  0.000  0.500  1.0
  O  O14  1  0.000  0.500  0.000  1.0
  O  O15  1  0.500  0.500  0.000  1.0
[/CIF]
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The material described by KMg6CrO8 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. K(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form KO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent K(1)O6 octahedra, edges with four equivalent Cr(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent K(1)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, edges with four equivalent Mg(2)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. In the second Mg site, Mg(2) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form MgO6 octahedra that share corners with two equivalent Cr(1)O6 octahedra, corners with four equivalent Mg(2)O6 octahedra, edges with four equivalent Mg(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. In the third Mg site, Mg(3) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Mg(3)O6 octahedra, edges with two equivalent K(1)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mg(2)O6 octahedra, edges with two equivalent Cr(1)O6 octahedra, and edges with four equivalent Mg(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. Cr(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form CrO6 octahedra that share corners with two equivalent Mg(2)O6 octahedra, corners with four equivalent Cr(1)O6 octahedra, edges with four equivalent K(1)O6 octahedra, and edges with eight equivalent Mg(3)O6 octahedra. The corner-sharing octahedra are not tilted. There are four inequivalent O sites. In the first O site, O(1) is bonded to one K(1), one Mg(1), and four equivalent Mg(3) atoms to form OKMg5 octahedra that share corners with six equivalent O(1)KMg5 octahedra, edges with four equivalent O(3)K2Mg2Cr2 octahedra, edges with four equivalent O(2)Mg5Cr octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-10°. In the second O site, O(2) is bonded to one Mg(2), four equivalent Mg(3), and one Cr(1) atom to form OMg5Cr octahedra that share corners with six equivalent O(2)Mg5Cr octahedra, edges with four equivalent O(3)K2Mg2Cr2 octahedra, edges with four equivalent O(1)KMg5 octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedral tilt angles range from 0-7°. In the third O site, O(3) is bonded to two equivalent K(1), two equivalent Mg(3), and two equivalent Cr(1) atoms to form OK2Mg2Cr2 octahedra that share corners with two equivalent O(4)Mg6 octahedra, corners with four equivalent O(3)K2Mg2Cr2 octahedra, edges with four equivalent O(3)K2Mg2Cr2 octahedra, edges with four equivalent O(1)KMg5 octahedra, and edges with four equivalent O(2)Mg5Cr octahedra. The corner-sharing octahedra are not tilted. In the fourth O site, O(4) is bonded to two equivalent Mg(1), two equivalent Mg(2), and two equivalent Mg(3) atoms to form OMg6 octahedra that share corners with two equivalent O(3)K2Mg2Cr2 octahedra, corners with four equivalent O(4)Mg6 octahedra, edges with four equivalent O(1)KMg5 octahedra, edges with four equivalent O(2)Mg5Cr octahedra, and edges with four equivalent O(4)Mg6 octahedra. The corner-sharing octahedra are not tilted. is represented by the CIF card [CIF]
data_KMg6CrO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.739
_cell_length_b   4.415
_cell_length_c   4.415
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   170.376
_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
  K  K0  1  0.000  0.000  0.000  1.0
  Mg  Mg1  1  0.500  0.000  0.000  1.0
  Mg  Mg2  1  0.500  0.500  0.500  1.0
  Mg  Mg3  1  0.254  0.000  0.500  1.0
  Mg  Mg4  1  0.746  0.000  0.500  1.0
  Mg  Mg5  1  0.254  0.500  0.000  1.0
  Mg  Mg6  1  0.746  0.500  0.000  1.0
  Cr  Cr7  1  0.000  0.500  0.500  1.0
  O  O8  1  0.276  0.000  0.000  1.0
  O  O9  1  0.724  0.000  0.000  1.0
  O  O10  1  0.238  0.500  0.500  1.0
  O  O11  1  0.762  0.500  0.500  1.0
  O  O12  1  0.000  0.000  0.500  1.0
  O  O13  1  0.500  0.000  0.500  1.0
  O  O14  1  0.000  0.500  0.000  1.0
  O  O15  1  0.500  0.500  0.000  1.0
[/CIF]
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