The compound described by K3Mg2Cl7 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to four equivalent Cl(1) and five equivalent Cl(2) atoms. In the second K site, K(2) is bonded to four equivalent Cl(3) and eight equivalent Cl(1) atoms to form KCl12 cuboctahedra that share corners with four equivalent K(2)Cl12 cuboctahedra, faces with four equivalent K(2)Cl12 cuboctahedra, and faces with eight equivalent Mg(1)Cl6 octahedra. Mg(1) is bonded to one Cl(2), one Cl(3), and four equivalent Cl(1) atoms to form MgCl6 octahedra that share corners with five equivalent Mg(1)Cl6 octahedra and faces with four equivalent K(2)Cl12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-4°. There are three inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to two equivalent K(1), two equivalent K(2), and two equivalent Mg(1) atoms to form distorted ClK4Mg2 octahedra that share corners with six equivalent Cl(2)K5Mg octahedra, corners with eight equivalent Cl(1)K4Mg2 octahedra, edges with three equivalent Cl(1)K4Mg2 octahedra, faces with two equivalent Cl(2)K5Mg octahedra, and faces with four equivalent Cl(1)K4Mg2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°. In the second Cl site, Cl(2) is bonded to five equivalent K(1) and one Mg(1) atom to form distorted ClK5Mg octahedra that share corners with four equivalent Cl(2)K5Mg octahedra, corners with twelve equivalent Cl(1)K4Mg2 octahedra, edges with eight equivalent Cl(2)K5Mg octahedra, and faces with four equivalent Cl(1)K4Mg2 octahedra. The corner-sharing octahedral tilt angles range from 12-53°. In the third Cl site, Cl(3) is bonded in a distorted linear geometry to four equivalent K(2) and two equivalent Mg(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_K3Mg2Cl7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.156
_cell_length_b   13.156
_cell_length_c   13.156
_cell_angle_alpha   158.305
_cell_angle_beta   158.305
_cell_angle_gamma   30.870
_symmetry_Int_Tables_number   1
_cell_volume   310.957
_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  0.318  0.318  0.000  1.0
  K  K1  1  0.682  0.682  0.000  1.0
  K  K2  1  0.500  0.500  0.000  1.0
  Mg  Mg3  1  0.099  0.099  0.000  1.0
  Mg  Mg4  1  0.901  0.901  0.000  1.0
  Cl  Cl5  1  0.596  0.096  0.500  1.0
  Cl  Cl6  1  0.404  0.904  0.500  1.0
  Cl  Cl7  1  0.096  0.596  0.500  1.0
  Cl  Cl8  1  0.904  0.404  0.500  1.0
  Cl  Cl9  1  0.196  0.196  0.000  1.0
  Cl  Cl10  1  0.804  0.804  0.000  1.0
  Cl  Cl11  1  0.000  0.000  0.000  1.0
[/CIF]
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The compound described by K3Mg2Cl7 crystallizes in the tetragonal I4/mmm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to four equivalent Cl(1) and five equivalent Cl(2) atoms. In the second K site, K(2) is bonded to four equivalent Cl(3) and eight equivalent Cl(1) atoms to form KCl12 cuboctahedra that share corners with four equivalent K(2)Cl12 cuboctahedra, faces with four equivalent K(2)Cl12 cuboctahedra, and faces with eight equivalent Mg(1)Cl6 octahedra. Mg(1) is bonded to one Cl(2), one Cl(3), and four equivalent Cl(1) atoms to form MgCl6 octahedra that share corners with five equivalent Mg(1)Cl6 octahedra and faces with four equivalent K(2)Cl12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-4°. There are three inequivalent Cl sites. In the first Cl site, Cl(1) is bonded to two equivalent K(1), two equivalent K(2), and two equivalent Mg(1) atoms to form distorted ClK4Mg2 octahedra that share corners with six equivalent Cl(2)K5Mg octahedra, corners with eight equivalent Cl(1)K4Mg2 octahedra, edges with three equivalent Cl(1)K4Mg2 octahedra, faces with two equivalent Cl(2)K5Mg octahedra, and faces with four equivalent Cl(1)K4Mg2 octahedra. The corner-sharing octahedral tilt angles range from 0-61°. In the second Cl site, Cl(2) is bonded to five equivalent K(1) and one Mg(1) atom to form distorted ClK5Mg octahedra that share corners with four equivalent Cl(2)K5Mg octahedra, corners with twelve equivalent Cl(1)K4Mg2 octahedra, edges with eight equivalent Cl(2)K5Mg octahedra, and faces with four equivalent Cl(1)K4Mg2 octahedra. The corner-sharing octahedral tilt angles range from 12-53°. In the third Cl site, Cl(3) is bonded in a distorted linear geometry to four equivalent K(2) and two equivalent Mg(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_K3Mg2Cl7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.156
_cell_length_b   13.156
_cell_length_c   13.156
_cell_angle_alpha   158.305
_cell_angle_beta   158.305
_cell_angle_gamma   30.870
_symmetry_Int_Tables_number   1
_cell_volume   310.957
_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  0.318  0.318  0.000  1.0
  K  K1  1  0.682  0.682  0.000  1.0
  K  K2  1  0.500  0.500  0.000  1.0
  Mg  Mg3  1  0.099  0.099  0.000  1.0
  Mg  Mg4  1  0.901  0.901  0.000  1.0
  Cl  Cl5  1  0.596  0.096  0.500  1.0
  Cl  Cl6  1  0.404  0.904  0.500  1.0
  Cl  Cl7  1  0.096  0.596  0.500  1.0
  Cl  Cl8  1  0.904  0.404  0.500  1.0
  Cl  Cl9  1  0.196  0.196  0.000  1.0
  Cl  Cl10  1  0.804  0.804  0.000  1.0
  Cl  Cl11  1  0.000  0.000  0.000  1.0
[/CIF]
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