The structure described by K2LaTa5O15 crystallizes in the tetragonal P4/mbm space group. K(1) is bonded in a 9-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), and four equivalent O(4) atoms. La(1) is bonded to four equivalent O(3) and eight equivalent O(5) atoms to form LaO12 cuboctahedra that share faces with two equivalent La(1)O12 cuboctahedra and faces with eight equivalent Ta(2)O6 octahedra. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 0-32°. In the second Ta site, Ta(2) is bonded to one O(2), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra, corners with five equivalent Ta(2)O6 octahedra, and faces with two equivalent La(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 10-36°. There are five inequivalent O sites. In the first O site, O(5) is bonded in a distorted linear geometry to two equivalent La(1) and two equivalent Ta(2) atoms. In the second O site, O(1) is bonded in a linear geometry to two equivalent K(1) and two equivalent Ta(1) atoms. In the third O site, O(2) is bonded in a 4-coordinate geometry to two equivalent K(1) and two equivalent Ta(2) atoms. In the fourth O site, O(3) is bonded in a 2-coordinate geometry to one K(1), one La(1), and two equivalent Ta(2) atoms. In the fifth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Ta(1), and one Ta(2) atom. is represented by the CIF card [CIF]
data_K2LaTa5O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.715
_cell_length_b   12.715
_cell_length_c   3.953
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   639.042
_cell_formula_units_Z   2
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  0.671  0.171  0.000  1.0
  K  K1  1  0.329  0.829  0.000  1.0
  K  K2  1  0.171  0.329  0.000  1.0
  K  K3  1  0.829  0.671  0.000  1.0
  La  La4  1  0.500  0.500  0.000  1.0
  La  La5  1  0.000  0.000  0.000  1.0
  Ta  Ta6  1  0.500  0.000  0.500  1.0
  Ta  Ta7  1  0.000  0.500  0.500  1.0
  Ta  Ta8  1  0.575  0.715  0.500  1.0
  Ta  Ta9  1  0.425  0.285  0.500  1.0
  Ta  Ta10  1  0.075  0.785  0.500  1.0
  Ta  Ta11  1  0.925  0.215  0.500  1.0
  Ta  Ta12  1  0.285  0.575  0.500  1.0
  Ta  Ta13  1  0.715  0.425  0.500  1.0
  Ta  Ta14  1  0.215  0.075  0.500  1.0
  Ta  Ta15  1  0.785  0.925  0.500  1.0
  O  O16  1  0.500  0.000  0.000  1.0
  O  O17  1  0.000  0.500  0.000  1.0
  O  O18  1  0.785  0.285  0.500  1.0
  O  O19  1  0.215  0.715  0.500  1.0
  O  O20  1  0.285  0.215  0.500  1.0
  O  O21  1  0.715  0.785  0.500  1.0
  O  O22  1  0.575  0.696  0.000  1.0
  O  O23  1  0.425  0.304  0.000  1.0
  O  O24  1  0.075  0.804  0.000  1.0
  O  O25  1  0.925  0.196  0.000  1.0
  O  O26  1  0.304  0.575  0.000  1.0
  O  O27  1  0.696  0.425  0.000  1.0
  O  O28  1  0.196  0.075  0.000  1.0
  O  O29  1  0.804  0.925  0.000  1.0
  O  O30  1  0.843  0.503  0.500  1.0
  O  O31  1  0.157  0.497  0.500  1.0
  O  O32  1  0.343  0.997  0.500  1.0
  O  O33  1  0.657  0.003  0.500  1.0
  O  O34  1  0.497  0.843  0.500  1.0
  O  O35  1  0.503  0.157  0.500  1.0
  O  O36  1  0.003  0.343  0.500  1.0
  O  O37  1  0.997  0.657  0.500  1.0
  O  O38  1  0.633  0.563  0.500  1.0
  O  O39  1  0.367  0.437  0.500  1.0
  O  O40  1  0.133  0.937  0.500  1.0
  O  O41  1  0.867  0.063  0.500  1.0
  O  O42  1  0.437  0.633  0.500  1.0
  O  O43  1  0.563  0.367  0.500  1.0
  O  O44  1  0.063  0.133  0.500  1.0
  O  O45  1  0.937  0.867  0.500  1.0
[/CIF]
.
The structure described by K2LaTa5O15 crystallizes in the tetragonal P4/mbm space group. K(1) is bonded in a 9-coordinate geometry to one O(1), two equivalent O(2), two equivalent O(3), and four equivalent O(4) atoms. La(1) is bonded to four equivalent O(3) and eight equivalent O(5) atoms to form LaO12 cuboctahedra that share faces with two equivalent La(1)O12 cuboctahedra and faces with eight equivalent Ta(2)O6 octahedra. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 0-32°. In the second Ta site, Ta(2) is bonded to one O(2), one O(4), two equivalent O(3), and two equivalent O(5) atoms to form TaO6 octahedra that share  a cornercorner with one Ta(1)O6 octahedra, corners with five equivalent Ta(2)O6 octahedra, and faces with two equivalent La(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 10-36°. There are five inequivalent O sites. In the first O site, O(5) is bonded in a distorted linear geometry to two equivalent La(1) and two equivalent Ta(2) atoms. In the second O site, O(1) is bonded in a linear geometry to two equivalent K(1) and two equivalent Ta(1) atoms. In the third O site, O(2) is bonded in a 4-coordinate geometry to two equivalent K(1) and two equivalent Ta(2) atoms. In the fourth O site, O(3) is bonded in a 2-coordinate geometry to one K(1), one La(1), and two equivalent Ta(2) atoms. In the fifth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Ta(1), and one Ta(2) atom. is represented by the CIF card [CIF]
data_K2LaTa5O15
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.715
_cell_length_b   12.715
_cell_length_c   3.953
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   639.042
_cell_formula_units_Z   2
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  0.671  0.171  0.000  1.0
  K  K1  1  0.329  0.829  0.000  1.0
  K  K2  1  0.171  0.329  0.000  1.0
  K  K3  1  0.829  0.671  0.000  1.0
  La  La4  1  0.500  0.500  0.000  1.0
  La  La5  1  0.000  0.000  0.000  1.0
  Ta  Ta6  1  0.500  0.000  0.500  1.0
  Ta  Ta7  1  0.000  0.500  0.500  1.0
  Ta  Ta8  1  0.575  0.715  0.500  1.0
  Ta  Ta9  1  0.425  0.285  0.500  1.0
  Ta  Ta10  1  0.075  0.785  0.500  1.0
  Ta  Ta11  1  0.925  0.215  0.500  1.0
  Ta  Ta12  1  0.285  0.575  0.500  1.0
  Ta  Ta13  1  0.715  0.425  0.500  1.0
  Ta  Ta14  1  0.215  0.075  0.500  1.0
  Ta  Ta15  1  0.785  0.925  0.500  1.0
  O  O16  1  0.500  0.000  0.000  1.0
  O  O17  1  0.000  0.500  0.000  1.0
  O  O18  1  0.785  0.285  0.500  1.0
  O  O19  1  0.215  0.715  0.500  1.0
  O  O20  1  0.285  0.215  0.500  1.0
  O  O21  1  0.715  0.785  0.500  1.0
  O  O22  1  0.575  0.696  0.000  1.0
  O  O23  1  0.425  0.304  0.000  1.0
  O  O24  1  0.075  0.804  0.000  1.0
  O  O25  1  0.925  0.196  0.000  1.0
  O  O26  1  0.304  0.575  0.000  1.0
  O  O27  1  0.696  0.425  0.000  1.0
  O  O28  1  0.196  0.075  0.000  1.0
  O  O29  1  0.804  0.925  0.000  1.0
  O  O30  1  0.843  0.503  0.500  1.0
  O  O31  1  0.157  0.497  0.500  1.0
  O  O32  1  0.343  0.997  0.500  1.0
  O  O33  1  0.657  0.003  0.500  1.0
  O  O34  1  0.497  0.843  0.500  1.0
  O  O35  1  0.503  0.157  0.500  1.0
  O  O36  1  0.003  0.343  0.500  1.0
  O  O37  1  0.997  0.657  0.500  1.0
  O  O38  1  0.633  0.563  0.500  1.0
  O  O39  1  0.367  0.437  0.500  1.0
  O  O40  1  0.133  0.937  0.500  1.0
  O  O41  1  0.867  0.063  0.500  1.0
  O  O42  1  0.437  0.633  0.500  1.0
  O  O43  1  0.563  0.367  0.500  1.0
  O  O44  1  0.063  0.133  0.500  1.0
  O  O45  1  0.937  0.867  0.500  1.0
[/CIF]
.