The structure described by K2TaF7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one F(1), one F(2), one F(3), one F(6), one F(7), two equivalent F(4), and two equivalent F(5) atoms. In the second K site, K(2) is bonded in a 9-coordinate geometry to one F(1), one F(2), one F(3), one F(4), one F(5), two equivalent F(6), and two equivalent F(7) atoms. Ta(1) is bonded in a distorted pentagonal bipyramidal geometry to one F(1), one F(2), one F(3), one F(4), one F(5), one F(6), and one F(7) atom. There are seven inequivalent F sites. In the first F site, F(6) is bonded to one K(1), two equivalent K(2), and one Ta(1) atom to form a mixture of distorted corner and edge-sharing FK3Ta tetrahedra. In the second F site, F(7) is bonded to one K(1), two equivalent K(2), and one Ta(1) atom to form a mixture of distorted corner and edge-sharing FK3Ta tetrahedra. In the third F site, F(1) is bonded in a distorted trigonal non-coplanar geometry to one K(1), one K(2), and one Ta(1) atom. In the fourth F site, F(2) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one Ta(1) atom. In the fifth F site, F(3) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one Ta(1) atom. In the sixth F site, F(4) is bonded to one K(2), two equivalent K(1), and one Ta(1) atom to form a mixture of distorted corner and edge-sharing FK3Ta tetrahedra. In the seventh F site, F(5) is bonded to one K(2), two equivalent K(1), and one Ta(1) atom to form a mixture of distorted corner and edge-sharing FK3Ta tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2TaF7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.636
_cell_length_b   5.786
_cell_length_c   8.460
_cell_angle_alpha   90.065
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   618.593
_cell_formula_units_Z   4
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  0.218  0.761  0.054  1.0
  K  K1  1  0.718  0.239  0.446  1.0
  K  K2  1  0.782  0.239  0.946  1.0
  K  K3  1  0.282  0.761  0.554  1.0
  K  K4  1  0.059  0.236  0.319  1.0
  K  K5  1  0.559  0.764  0.181  1.0
  K  K6  1  0.941  0.764  0.681  1.0
  K  K7  1  0.441  0.236  0.819  1.0
  Ta  Ta8  1  0.371  0.272  0.278  1.0
  Ta  Ta9  1  0.871  0.728  0.222  1.0
  Ta  Ta10  1  0.629  0.728  0.722  1.0
  Ta  Ta11  1  0.129  0.272  0.778  1.0
  F  F12  1  0.423  0.564  0.370  1.0
  F  F13  1  0.923  0.436  0.130  1.0
  F  F14  1  0.577  0.436  0.630  1.0
  F  F15  1  0.077  0.564  0.870  1.0
  F  F16  1  0.377  0.188  0.500  1.0
  F  F17  1  0.877  0.812  1.000  1.0
  F  F18  1  0.623  0.812  0.500  1.0
  F  F19  1  0.123  0.188  0.000  1.0
  F  F20  1  0.523  0.209  0.286  1.0
  F  F21  1  0.023  0.791  0.214  1.0
  F  F22  1  0.477  0.791  0.714  1.0
  F  F23  1  0.977  0.209  0.786  1.0
  F  F24  1  0.244  0.042  0.801  1.0
  F  F25  1  0.744  0.958  0.699  1.0
  F  F26  1  0.756  0.958  0.199  1.0
  F  F27  1  0.256  0.042  0.301  1.0
  F  F28  1  0.258  0.461  0.791  1.0
  F  F29  1  0.758  0.539  0.709  1.0
  F  F30  1  0.742  0.539  0.209  1.0
  F  F31  1  0.242  0.461  0.291  1.0
  F  F32  1  0.108  0.041  0.608  1.0
  F  F33  1  0.608  0.959  0.892  1.0
  F  F34  1  0.892  0.959  0.392  1.0
  F  F35  1  0.392  0.041  0.108  1.0
  F  F36  1  0.110  0.465  0.588  1.0
  F  F37  1  0.610  0.535  0.912  1.0
  F  F38  1  0.890  0.535  0.412  1.0
  F  F39  1  0.390  0.465  0.088  1.0
[/CIF]
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The structure described by K2TaF7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 9-coordinate geometry to one F(1), one F(2), one F(3), one F(6), one F(7), two equivalent F(4), and two equivalent F(5) atoms. In the second K site, K(2) is bonded in a 9-coordinate geometry to one F(1), one F(2), one F(3), one F(4), one F(5), two equivalent F(6), and two equivalent F(7) atoms. Ta(1) is bonded in a distorted pentagonal bipyramidal geometry to one F(1), one F(2), one F(3), one F(4), one F(5), one F(6), and one F(7) atom. There are seven inequivalent F sites. In the first F site, F(6) is bonded to one K(1), two equivalent K(2), and one Ta(1) atom to form a mixture of distorted corner and edge-sharing FK3Ta tetrahedra. In the second F site, F(7) is bonded to one K(1), two equivalent K(2), and one Ta(1) atom to form a mixture of distorted corner and edge-sharing FK3Ta tetrahedra. In the third F site, F(1) is bonded in a distorted trigonal non-coplanar geometry to one K(1), one K(2), and one Ta(1) atom. In the fourth F site, F(2) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one Ta(1) atom. In the fifth F site, F(3) is bonded in a distorted single-bond geometry to one K(1), one K(2), and one Ta(1) atom. In the sixth F site, F(4) is bonded to one K(2), two equivalent K(1), and one Ta(1) atom to form a mixture of distorted corner and edge-sharing FK3Ta tetrahedra. In the seventh F site, F(5) is bonded to one K(2), two equivalent K(1), and one Ta(1) atom to form a mixture of distorted corner and edge-sharing FK3Ta tetrahedra. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2TaF7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.636
_cell_length_b   5.786
_cell_length_c   8.460
_cell_angle_alpha   90.065
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   618.593
_cell_formula_units_Z   4
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  0.218  0.761  0.054  1.0
  K  K1  1  0.718  0.239  0.446  1.0
  K  K2  1  0.782  0.239  0.946  1.0
  K  K3  1  0.282  0.761  0.554  1.0
  K  K4  1  0.059  0.236  0.319  1.0
  K  K5  1  0.559  0.764  0.181  1.0
  K  K6  1  0.941  0.764  0.681  1.0
  K  K7  1  0.441  0.236  0.819  1.0
  Ta  Ta8  1  0.371  0.272  0.278  1.0
  Ta  Ta9  1  0.871  0.728  0.222  1.0
  Ta  Ta10  1  0.629  0.728  0.722  1.0
  Ta  Ta11  1  0.129  0.272  0.778  1.0
  F  F12  1  0.423  0.564  0.370  1.0
  F  F13  1  0.923  0.436  0.130  1.0
  F  F14  1  0.577  0.436  0.630  1.0
  F  F15  1  0.077  0.564  0.870  1.0
  F  F16  1  0.377  0.188  0.500  1.0
  F  F17  1  0.877  0.812  1.000  1.0
  F  F18  1  0.623  0.812  0.500  1.0
  F  F19  1  0.123  0.188  0.000  1.0
  F  F20  1  0.523  0.209  0.286  1.0
  F  F21  1  0.023  0.791  0.214  1.0
  F  F22  1  0.477  0.791  0.714  1.0
  F  F23  1  0.977  0.209  0.786  1.0
  F  F24  1  0.244  0.042  0.801  1.0
  F  F25  1  0.744  0.958  0.699  1.0
  F  F26  1  0.756  0.958  0.199  1.0
  F  F27  1  0.256  0.042  0.301  1.0
  F  F28  1  0.258  0.461  0.791  1.0
  F  F29  1  0.758  0.539  0.709  1.0
  F  F30  1  0.742  0.539  0.209  1.0
  F  F31  1  0.242  0.461  0.291  1.0
  F  F32  1  0.108  0.041  0.608  1.0
  F  F33  1  0.608  0.959  0.892  1.0
  F  F34  1  0.892  0.959  0.392  1.0
  F  F35  1  0.392  0.041  0.108  1.0
  F  F36  1  0.110  0.465  0.588  1.0
  F  F37  1  0.610  0.535  0.912  1.0
  F  F38  1  0.890  0.535  0.412  1.0
  F  F39  1  0.390  0.465  0.088  1.0
[/CIF]
.