The crystal structure described by K2SrTa2O7 crystallizes in the tetragonal I4/mmm space group. K(1) is bonded in a 9-coordinate geometry to four equivalent O(3) and five equivalent O(2) atoms. Sr(1) is bonded to four equivalent O(1) and eight equivalent O(3) atoms to form SrO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Sr(1)O12 cuboctahedra, and faces with eight equivalent Ta(1)O6 octahedra. Ta(1) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form TaO6 octahedra that share corners with five equivalent Ta(1)O6 octahedra and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-11°. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Ta(1) atoms to form distorted OSr4Ta2 octahedra that share corners with two equivalent O(2)K5Ta octahedra, corners with four equivalent O(1)Sr4Ta2 octahedra, and edges with four equivalent O(1)Sr4Ta2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to five equivalent K(1) and one Ta(1) atom to form distorted OK5Ta octahedra that share  a cornercorner with one O(1)Sr4Ta2 octahedra, corners with four equivalent O(2)K5Ta octahedra, and edges with eight equivalent O(2)K5Ta octahedra. The corner-sharing octahedral tilt angles range from 0-11°. In the third O site, O(3) is bonded in a distorted linear geometry to two equivalent K(1), two equivalent Sr(1), and two equivalent Ta(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2SrTa2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.404
_cell_length_b   11.404
_cell_length_c   11.404
_cell_angle_alpha   159.707
_cell_angle_beta   159.707
_cell_angle_gamma   28.852
_symmetry_Int_Tables_number   1
_cell_volume   178.292
_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  0.807  0.807  0.000  1.0
  K  K1  1  0.193  0.193  0.000  1.0
  Sr  Sr2  1  0.000  0.000  0.000  1.0
  Ta  Ta3  1  0.596  0.596  0.000  1.0
  Ta  Ta4  1  0.404  0.404  0.000  1.0
  O  O5  1  0.500  0.500  0.000  1.0
  O  O6  1  0.319  0.319  0.000  1.0
  O  O7  1  0.681  0.681  0.000  1.0
  O  O8  1  0.913  0.413  0.500  1.0
  O  O9  1  0.413  0.913  0.500  1.0
  O  O10  1  0.587  0.087  0.500  1.0
  O  O11  1  0.087  0.587  0.500  1.0
[/CIF]
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The crystal structure described by K2SrTa2O7 crystallizes in the tetragonal I4/mmm space group. K(1) is bonded in a 9-coordinate geometry to four equivalent O(3) and five equivalent O(2) atoms. Sr(1) is bonded to four equivalent O(1) and eight equivalent O(3) atoms to form SrO12 cuboctahedra that share corners with four equivalent Sr(1)O12 cuboctahedra, faces with four equivalent Sr(1)O12 cuboctahedra, and faces with eight equivalent Ta(1)O6 octahedra. Ta(1) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form TaO6 octahedra that share corners with five equivalent Ta(1)O6 octahedra and faces with four equivalent Sr(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-11°. There are three inequivalent O sites. In the first O site, O(1) is bonded to four equivalent Sr(1) and two equivalent Ta(1) atoms to form distorted OSr4Ta2 octahedra that share corners with two equivalent O(2)K5Ta octahedra, corners with four equivalent O(1)Sr4Ta2 octahedra, and edges with four equivalent O(1)Sr4Ta2 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to five equivalent K(1) and one Ta(1) atom to form distorted OK5Ta octahedra that share  a cornercorner with one O(1)Sr4Ta2 octahedra, corners with four equivalent O(2)K5Ta octahedra, and edges with eight equivalent O(2)K5Ta octahedra. The corner-sharing octahedral tilt angles range from 0-11°. In the third O site, O(3) is bonded in a distorted linear geometry to two equivalent K(1), two equivalent Sr(1), and two equivalent Ta(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2SrTa2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.404
_cell_length_b   11.404
_cell_length_c   11.404
_cell_angle_alpha   159.707
_cell_angle_beta   159.707
_cell_angle_gamma   28.852
_symmetry_Int_Tables_number   1
_cell_volume   178.292
_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  0.807  0.807  0.000  1.0
  K  K1  1  0.193  0.193  0.000  1.0
  Sr  Sr2  1  0.000  0.000  0.000  1.0
  Ta  Ta3  1  0.596  0.596  0.000  1.0
  Ta  Ta4  1  0.404  0.404  0.000  1.0
  O  O5  1  0.500  0.500  0.000  1.0
  O  O6  1  0.319  0.319  0.000  1.0
  O  O7  1  0.681  0.681  0.000  1.0
  O  O8  1  0.913  0.413  0.500  1.0
  O  O9  1  0.413  0.913  0.500  1.0
  O  O10  1  0.587  0.087  0.500  1.0
  O  O11  1  0.087  0.587  0.500  1.0
[/CIF]
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