The material described by Rb3Ta is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to four equivalent Rb(2) and four equivalent Ta(1) atoms to form distorted RbRb4Ta4 cuboctahedra that share corners with eight equivalent Rb(1)Rb4Ta4 cuboctahedra, corners with eight equivalent Rb(2)Rb8Ta4 cuboctahedra, corners with eight equivalent Ta(1)Rb12 cuboctahedra, edges with four equivalent Rb(2)Rb8Ta4 cuboctahedra, edges with four equivalent Ta(1)Rb12 cuboctahedra, edges with twelve equivalent Rb(1)Rb4Ta4 cuboctahedra, and faces with six equivalent Rb(1)Rb4Ta4 cuboctahedra. In the second Rb site, Rb(2) is bonded to eight equivalent Rb(1) and four equivalent Ta(1) atoms to form RbRb8Ta4 cuboctahedra that share corners with four equivalent Rb(2)Rb8Ta4 cuboctahedra, corners with eight equivalent Ta(1)Rb12 cuboctahedra, corners with sixteen equivalent Rb(1)Rb4Ta4 cuboctahedra, edges with eight equivalent Rb(1)Rb4Ta4 cuboctahedra, edges with eight equivalent Rb(2)Rb8Ta4 cuboctahedra, faces with four equivalent Rb(2)Rb8Ta4 cuboctahedra, and faces with six equivalent Ta(1)Rb12 cuboctahedra. Ta(1) is bonded to four equivalent Rb(2) and eight equivalent Rb(1) atoms to form TaRb12 cuboctahedra that share corners with four equivalent Ta(1)Rb12 cuboctahedra, corners with eight equivalent Rb(2)Rb8Ta4 cuboctahedra, corners with sixteen equivalent Rb(1)Rb4Ta4 cuboctahedra, edges with eight equivalent Rb(1)Rb4Ta4 cuboctahedra, edges with eight equivalent Ta(1)Rb12 cuboctahedra, faces with four equivalent Ta(1)Rb12 cuboctahedra, and faces with six equivalent Rb(2)Rb8Ta4 cuboctahedra. is represented by the CIF file [CIF]
data_Rb3Ta
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.182
_cell_length_b   7.182
_cell_length_c   7.182
_cell_angle_alpha   129.662
_cell_angle_beta   129.662
_cell_angle_gamma   73.947
_symmetry_Int_Tables_number   1
_cell_volume   214.125
_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
  Rb  Rb0  1  0.750  0.250  0.500  1.0
  Rb  Rb1  1  0.250  0.750  0.500  1.0
  Rb  Rb2  1  0.500  0.500  0.000  1.0
  Ta  Ta3  1  0.000  0.000  0.000  1.0
[/CIF]
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The material described by Rb3Ta is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to four equivalent Rb(2) and four equivalent Ta(1) atoms to form distorted RbRb4Ta4 cuboctahedra that share corners with eight equivalent Rb(1)Rb4Ta4 cuboctahedra, corners with eight equivalent Rb(2)Rb8Ta4 cuboctahedra, corners with eight equivalent Ta(1)Rb12 cuboctahedra, edges with four equivalent Rb(2)Rb8Ta4 cuboctahedra, edges with four equivalent Ta(1)Rb12 cuboctahedra, edges with twelve equivalent Rb(1)Rb4Ta4 cuboctahedra, and faces with six equivalent Rb(1)Rb4Ta4 cuboctahedra. In the second Rb site, Rb(2) is bonded to eight equivalent Rb(1) and four equivalent Ta(1) atoms to form RbRb8Ta4 cuboctahedra that share corners with four equivalent Rb(2)Rb8Ta4 cuboctahedra, corners with eight equivalent Ta(1)Rb12 cuboctahedra, corners with sixteen equivalent Rb(1)Rb4Ta4 cuboctahedra, edges with eight equivalent Rb(1)Rb4Ta4 cuboctahedra, edges with eight equivalent Rb(2)Rb8Ta4 cuboctahedra, faces with four equivalent Rb(2)Rb8Ta4 cuboctahedra, and faces with six equivalent Ta(1)Rb12 cuboctahedra. Ta(1) is bonded to four equivalent Rb(2) and eight equivalent Rb(1) atoms to form TaRb12 cuboctahedra that share corners with four equivalent Ta(1)Rb12 cuboctahedra, corners with eight equivalent Rb(2)Rb8Ta4 cuboctahedra, corners with sixteen equivalent Rb(1)Rb4Ta4 cuboctahedra, edges with eight equivalent Rb(1)Rb4Ta4 cuboctahedra, edges with eight equivalent Ta(1)Rb12 cuboctahedra, faces with four equivalent Ta(1)Rb12 cuboctahedra, and faces with six equivalent Rb(2)Rb8Ta4 cuboctahedra. is represented by the CIF file [CIF]
data_Rb3Ta
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.182
_cell_length_b   7.182
_cell_length_c   7.182
_cell_angle_alpha   129.662
_cell_angle_beta   129.662
_cell_angle_gamma   73.947
_symmetry_Int_Tables_number   1
_cell_volume   214.125
_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
  Rb  Rb0  1  0.750  0.250  0.500  1.0
  Rb  Rb1  1  0.250  0.750  0.500  1.0
  Rb  Rb2  1  0.500  0.500  0.000  1.0
  Ta  Ta3  1  0.000  0.000  0.000  1.0
[/CIF]
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