The compound described by RbMgF3 is (Cubic) Perovskite-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to six equivalent F(1) and six equivalent F(2) atoms to form RbF12 cuboctahedra that share corners with six equivalent Rb(1)F12 cuboctahedra, corners with six equivalent Rb(2)F12 cuboctahedra, faces with six equivalent Rb(2)F12 cuboctahedra, faces with two equivalent Mg(1)F6 octahedra, and faces with six equivalent Mg(2)F6 octahedra. In the second Rb site, Rb(2) is bonded to three equivalent F(1) and nine equivalent F(2) atoms to form RbF12 cuboctahedra that share corners with three equivalent Rb(1)F12 cuboctahedra, corners with six equivalent Rb(2)F12 cuboctahedra, corners with three equivalent Mg(2)F6 octahedra, faces with three equivalent Rb(1)F12 cuboctahedra, faces with four equivalent Rb(2)F12 cuboctahedra, faces with three equivalent Mg(1)F6 octahedra, and faces with four equivalent Mg(2)F6 octahedra. The corner-sharing octahedral tilt angles are 6°. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to six equivalent F(2) atoms to form MgF6 octahedra that share corners with six equivalent Mg(2)F6 octahedra, faces with two equivalent Rb(1)F12 cuboctahedra, and faces with six equivalent Rb(2)F12 cuboctahedra. The corner-sharing octahedral tilt angles are 2°. In the second Mg site, Mg(2) is bonded to three equivalent F(1) and three equivalent F(2) atoms to form MgF6 octahedra that share corners with three equivalent Rb(2)F12 cuboctahedra, corners with three equivalent Mg(1)F6 octahedra, faces with three equivalent Rb(1)F12 cuboctahedra, faces with four equivalent Rb(2)F12 cuboctahedra, and  a faceface with one Mg(2)F6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted L-shaped geometry to two equivalent Rb(1), two equivalent Rb(2), and two equivalent Mg(2) atoms. In the second F site, F(2) is bonded in a distorted linear geometry to one Rb(1), three equivalent Rb(2), one Mg(1), and one Mg(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_RbMgF3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.822
_cell_length_b   5.822
_cell_length_c   14.183
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.998
_symmetry_Int_Tables_number   1
_cell_volume   416.376
_cell_formula_units_Z   6
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
  Rb  Rb0  1  0.000  1.000  0.250  1.0
  Rb  Rb1  1  1.000  0.000  0.750  1.0
  Rb  Rb2  1  0.333  0.667  0.098  1.0
  Rb  Rb3  1  0.667  0.333  0.598  1.0
  Rb  Rb4  1  0.667  0.333  0.902  1.0
  Rb  Rb5  1  0.333  0.667  0.402  1.0
  Mg  Mg6  1  0.000  1.000  1.000  1.0
  Mg  Mg7  1  0.000  1.000  0.500  1.0
  Mg  Mg8  1  0.333  0.667  0.847  1.0
  Mg  Mg9  1  0.667  0.333  0.347  1.0
  Mg  Mg10  1  0.667  0.333  0.153  1.0
  Mg  Mg11  1  0.333  0.667  0.653  1.0
  F  F12  1  0.520  0.040  0.250  1.0
  F  F13  1  0.480  0.520  0.750  1.0
  F  F14  1  0.040  0.520  0.750  1.0
  F  F15  1  0.960  0.480  0.250  1.0
  F  F16  1  0.520  0.480  0.250  1.0
  F  F17  1  0.480  0.960  0.750  1.0
  F  F18  1  0.834  0.668  0.080  1.0
  F  F19  1  0.166  0.834  0.580  1.0
  F  F20  1  0.668  0.834  0.580  1.0
  F  F21  1  0.332  0.166  0.080  1.0
  F  F22  1  0.834  0.166  0.080  1.0
  F  F23  1  0.166  0.332  0.920  1.0
  F  F24  1  0.166  0.834  0.920  1.0
  F  F25  1  0.166  0.332  0.580  1.0
  F  F26  1  0.668  0.834  0.920  1.0
  F  F27  1  0.332  0.166  0.420  1.0
  F  F28  1  0.834  0.668  0.420  1.0
  F  F29  1  0.834  0.166  0.420  1.0
[/CIF]
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The compound described by RbMgF3 is (Cubic) Perovskite-like structured and crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to six equivalent F(1) and six equivalent F(2) atoms to form RbF12 cuboctahedra that share corners with six equivalent Rb(1)F12 cuboctahedra, corners with six equivalent Rb(2)F12 cuboctahedra, faces with six equivalent Rb(2)F12 cuboctahedra, faces with two equivalent Mg(1)F6 octahedra, and faces with six equivalent Mg(2)F6 octahedra. In the second Rb site, Rb(2) is bonded to three equivalent F(1) and nine equivalent F(2) atoms to form RbF12 cuboctahedra that share corners with three equivalent Rb(1)F12 cuboctahedra, corners with six equivalent Rb(2)F12 cuboctahedra, corners with three equivalent Mg(2)F6 octahedra, faces with three equivalent Rb(1)F12 cuboctahedra, faces with four equivalent Rb(2)F12 cuboctahedra, faces with three equivalent Mg(1)F6 octahedra, and faces with four equivalent Mg(2)F6 octahedra. The corner-sharing octahedral tilt angles are 6°. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to six equivalent F(2) atoms to form MgF6 octahedra that share corners with six equivalent Mg(2)F6 octahedra, faces with two equivalent Rb(1)F12 cuboctahedra, and faces with six equivalent Rb(2)F12 cuboctahedra. The corner-sharing octahedral tilt angles are 2°. In the second Mg site, Mg(2) is bonded to three equivalent F(1) and three equivalent F(2) atoms to form MgF6 octahedra that share corners with three equivalent Rb(2)F12 cuboctahedra, corners with three equivalent Mg(1)F6 octahedra, faces with three equivalent Rb(1)F12 cuboctahedra, faces with four equivalent Rb(2)F12 cuboctahedra, and  a faceface with one Mg(2)F6 octahedra. The corner-sharing octahedral tilt angles are 2°. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted L-shaped geometry to two equivalent Rb(1), two equivalent Rb(2), and two equivalent Mg(2) atoms. In the second F site, F(2) is bonded in a distorted linear geometry to one Rb(1), three equivalent Rb(2), one Mg(1), and one Mg(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_RbMgF3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.822
_cell_length_b   5.822
_cell_length_c   14.183
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   119.998
_symmetry_Int_Tables_number   1
_cell_volume   416.376
_cell_formula_units_Z   6
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
  Rb  Rb0  1  0.000  1.000  0.250  1.0
  Rb  Rb1  1  1.000  0.000  0.750  1.0
  Rb  Rb2  1  0.333  0.667  0.098  1.0
  Rb  Rb3  1  0.667  0.333  0.598  1.0
  Rb  Rb4  1  0.667  0.333  0.902  1.0
  Rb  Rb5  1  0.333  0.667  0.402  1.0
  Mg  Mg6  1  0.000  1.000  1.000  1.0
  Mg  Mg7  1  0.000  1.000  0.500  1.0
  Mg  Mg8  1  0.333  0.667  0.847  1.0
  Mg  Mg9  1  0.667  0.333  0.347  1.0
  Mg  Mg10  1  0.667  0.333  0.153  1.0
  Mg  Mg11  1  0.333  0.667  0.653  1.0
  F  F12  1  0.520  0.040  0.250  1.0
  F  F13  1  0.480  0.520  0.750  1.0
  F  F14  1  0.040  0.520  0.750  1.0
  F  F15  1  0.960  0.480  0.250  1.0
  F  F16  1  0.520  0.480  0.250  1.0
  F  F17  1  0.480  0.960  0.750  1.0
  F  F18  1  0.834  0.668  0.080  1.0
  F  F19  1  0.166  0.834  0.580  1.0
  F  F20  1  0.668  0.834  0.580  1.0
  F  F21  1  0.332  0.166  0.080  1.0
  F  F22  1  0.834  0.166  0.080  1.0
  F  F23  1  0.166  0.332  0.920  1.0
  F  F24  1  0.166  0.834  0.920  1.0
  F  F25  1  0.166  0.332  0.580  1.0
  F  F26  1  0.668  0.834  0.920  1.0
  F  F27  1  0.332  0.166  0.420  1.0
  F  F28  1  0.834  0.668  0.420  1.0
  F  F29  1  0.834  0.166  0.420  1.0
[/CIF]
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