The material structure described by K3MgCu2F9 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal P4/mmm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to four equivalent F(1), four equivalent F(2), and four equivalent F(3) atoms to form KF12 cuboctahedra that share corners with four equivalent K(2)F12 cuboctahedra, corners with eight equivalent K(1)F12 cuboctahedra,  a faceface with one K(2)F12 cuboctahedra, faces with five equivalent K(1)F12 cuboctahedra, faces with four equivalent Mg(1)F6 octahedra, and faces with four equivalent Cu(1)F6 octahedra. In the second K site, K(2) is bonded to four equivalent F(4) and eight equivalent F(2) atoms to form KF12 cuboctahedra that share corners with four equivalent K(2)F12 cuboctahedra, corners with eight equivalent K(1)F12 cuboctahedra, faces with two equivalent K(1)F12 cuboctahedra, faces with four equivalent K(2)F12 cuboctahedra, and faces with eight equivalent Cu(1)F6 octahedra. Mg(1) is bonded to two equivalent F(3) and four equivalent F(1) atoms to form MgF6 octahedra that share corners with two equivalent Cu(1)F6 octahedra, corners with four equivalent Mg(1)F6 octahedra, and faces with eight equivalent K(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. Cu(1) is bonded to one F(3), one F(4), and four equivalent F(2) atoms to form CuF6 octahedra that share  a cornercorner with one Mg(1)F6 octahedra, corners with five equivalent Cu(1)F6 octahedra, faces with four equivalent K(1)F12 cuboctahedra, and faces with four equivalent K(2)F12 cuboctahedra. The corner-sharing octahedra are not tilted. There are four inequivalent F sites. In the first F site, F(1) is bonded in a distorted linear geometry to four equivalent K(1) and two equivalent Mg(1) atoms. In the second F site, F(2) is bonded to two equivalent K(1), two equivalent K(2), and two equivalent Cu(1) atoms to form a mixture of distorted edge, face, and corner-sharing FK4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the third F site, F(3) is bonded in a distorted linear geometry to four equivalent K(1), one Mg(1), and one Cu(1) atom. In the fourth F site, F(4) is bonded to four equivalent K(2) and two equivalent Cu(1) atoms to form a mixture of distorted edge, face, and corner-sharing FK4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. is represented by the Crystallographic Information File (CIF) [CIF]
data_K3MgCu2F9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.065
_cell_length_b   4.065
_cell_length_c   12.231
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   202.130
_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  0.832  1.0
  K  K1  1  0.000  0.000  0.168  1.0
  K  K2  1  0.000  0.000  0.500  1.0
  Mg  Mg3  1  0.500  0.500  0.000  1.0
  Cu  Cu4  1  0.500  0.500  0.333  1.0
  Cu  Cu5  1  0.500  0.500  0.667  1.0
  F  F6  1  0.500  0.000  0.000  1.0
  F  F7  1  0.500  0.000  0.334  1.0
  F  F8  1  0.500  0.000  0.666  1.0
  F  F9  1  0.500  0.500  0.835  1.0
  F  F10  1  0.500  0.500  0.165  1.0
  F  F11  1  0.500  0.500  0.500  1.0
  F  F12  1  0.000  0.500  0.000  1.0
  F  F13  1  0.000  0.500  0.334  1.0
  F  F14  1  0.000  0.500  0.666  1.0
[/CIF]
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The material structure described by K3MgCu2F9 is (Cubic) Perovskite-derived structured and crystallizes in the tetragonal P4/mmm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to four equivalent F(1), four equivalent F(2), and four equivalent F(3) atoms to form KF12 cuboctahedra that share corners with four equivalent K(2)F12 cuboctahedra, corners with eight equivalent K(1)F12 cuboctahedra,  a faceface with one K(2)F12 cuboctahedra, faces with five equivalent K(1)F12 cuboctahedra, faces with four equivalent Mg(1)F6 octahedra, and faces with four equivalent Cu(1)F6 octahedra. In the second K site, K(2) is bonded to four equivalent F(4) and eight equivalent F(2) atoms to form KF12 cuboctahedra that share corners with four equivalent K(2)F12 cuboctahedra, corners with eight equivalent K(1)F12 cuboctahedra, faces with two equivalent K(1)F12 cuboctahedra, faces with four equivalent K(2)F12 cuboctahedra, and faces with eight equivalent Cu(1)F6 octahedra. Mg(1) is bonded to two equivalent F(3) and four equivalent F(1) atoms to form MgF6 octahedra that share corners with two equivalent Cu(1)F6 octahedra, corners with four equivalent Mg(1)F6 octahedra, and faces with eight equivalent K(1)F12 cuboctahedra. The corner-sharing octahedra are not tilted. Cu(1) is bonded to one F(3), one F(4), and four equivalent F(2) atoms to form CuF6 octahedra that share  a cornercorner with one Mg(1)F6 octahedra, corners with five equivalent Cu(1)F6 octahedra, faces with four equivalent K(1)F12 cuboctahedra, and faces with four equivalent K(2)F12 cuboctahedra. The corner-sharing octahedra are not tilted. There are four inequivalent F sites. In the first F site, F(1) is bonded in a distorted linear geometry to four equivalent K(1) and two equivalent Mg(1) atoms. In the second F site, F(2) is bonded to two equivalent K(1), two equivalent K(2), and two equivalent Cu(1) atoms to form a mixture of distorted edge, face, and corner-sharing FK4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the third F site, F(3) is bonded in a distorted linear geometry to four equivalent K(1), one Mg(1), and one Cu(1) atom. In the fourth F site, F(4) is bonded to four equivalent K(2) and two equivalent Cu(1) atoms to form a mixture of distorted edge, face, and corner-sharing FK4Cu2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. is represented by the Crystallographic Information File (CIF) [CIF]
data_K3MgCu2F9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.065
_cell_length_b   4.065
_cell_length_c   12.231
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   202.130
_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  0.832  1.0
  K  K1  1  0.000  0.000  0.168  1.0
  K  K2  1  0.000  0.000  0.500  1.0
  Mg  Mg3  1  0.500  0.500  0.000  1.0
  Cu  Cu4  1  0.500  0.500  0.333  1.0
  Cu  Cu5  1  0.500  0.500  0.667  1.0
  F  F6  1  0.500  0.000  0.000  1.0
  F  F7  1  0.500  0.000  0.334  1.0
  F  F8  1  0.500  0.000  0.666  1.0
  F  F9  1  0.500  0.500  0.835  1.0
  F  F10  1  0.500  0.500  0.165  1.0
  F  F11  1  0.500  0.500  0.500  1.0
  F  F12  1  0.000  0.500  0.000  1.0
  F  F13  1  0.000  0.500  0.334  1.0
  F  F14  1  0.000  0.500  0.666  1.0
[/CIF]
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