The compound described by K2NbF7 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. Nb(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 Nb(1) atom to form a mixture of distorted edge and corner-sharing FK3Nb tetrahedra. In the second F site, F(7) is bonded to one K(1), two equivalent K(2), and one Nb(1) atom to form a mixture of distorted edge and corner-sharing FK3Nb 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 Nb(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 Nb(1) atom. In the fifth F site, F(3) is bonded in a 3-coordinate geometry to one K(1), one K(2), and one Nb(1) atom. In the sixth F site, F(4) is bonded to one K(2), two equivalent K(1), and one Nb(1) atom to form a mixture of edge and corner-sharing FK3Nb tetrahedra. In the seventh F site, F(5) is bonded to one K(2), two equivalent K(1), and one Nb(1) atom to form a mixture of distorted edge and corner-sharing FK3Nb tetrahedra. is represented by the CIF file [CIF]
data_K2NbF7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.669
_cell_length_b   5.774
_cell_length_c   8.493
_cell_angle_alpha   90.034
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   621.299
_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  0.782  0.763  0.055  1.0
  K  K1  1  0.282  0.237  0.445  1.0
  K  K2  1  0.218  0.237  0.945  1.0
  K  K3  1  0.718  0.763  0.555  1.0
  K  K4  1  0.940  0.238  0.320  1.0
  K  K5  1  0.440  0.762  0.180  1.0
  K  K6  1  0.060  0.762  0.680  1.0
  K  K7  1  0.560  0.238  0.820  1.0
  Nb  Nb8  1  0.628  0.273  0.280  1.0
  Nb  Nb9  1  0.128  0.727  0.220  1.0
  Nb  Nb10  1  0.372  0.727  0.720  1.0
  Nb  Nb11  1  0.872  0.273  0.780  1.0
  F  F12  1  0.576  0.568  0.372  1.0
  F  F13  1  0.076  0.432  0.128  1.0
  F  F14  1  0.424  0.432  0.628  1.0
  F  F15  1  0.924  0.568  0.872  1.0
  F  F16  1  0.623  0.189  0.503  1.0
  F  F17  1  0.123  0.811  0.997  1.0
  F  F18  1  0.377  0.811  0.497  1.0
  F  F19  1  0.877  0.189  0.003  1.0
  F  F20  1  0.475  0.211  0.288  1.0
  F  F21  1  0.975  0.789  0.212  1.0
  F  F22  1  0.525  0.789  0.712  1.0
  F  F23  1  0.025  0.211  0.788  1.0
  F  F24  1  0.755  0.042  0.802  1.0
  F  F25  1  0.255  0.958  0.698  1.0
  F  F26  1  0.245  0.958  0.198  1.0
  F  F27  1  0.745  0.042  0.302  1.0
  F  F28  1  0.742  0.466  0.794  1.0
  F  F29  1  0.242  0.534  0.706  1.0
  F  F30  1  0.258  0.534  0.206  1.0
  F  F31  1  0.758  0.466  0.294  1.0
  F  F32  1  0.893  0.041  0.608  1.0
  F  F33  1  0.393  0.959  0.892  1.0
  F  F34  1  0.107  0.959  0.392  1.0
  F  F35  1  0.607  0.041  0.108  1.0
  F  F36  1  0.891  0.469  0.589  1.0
  F  F37  1  0.391  0.531  0.911  1.0
  F  F38  1  0.109  0.531  0.411  1.0
  F  F39  1  0.609  0.469  0.089  1.0
[/CIF]
.
The compound described by K2NbF7 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. Nb(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 Nb(1) atom to form a mixture of distorted edge and corner-sharing FK3Nb tetrahedra. In the second F site, F(7) is bonded to one K(1), two equivalent K(2), and one Nb(1) atom to form a mixture of distorted edge and corner-sharing FK3Nb 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 Nb(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 Nb(1) atom. In the fifth F site, F(3) is bonded in a 3-coordinate geometry to one K(1), one K(2), and one Nb(1) atom. In the sixth F site, F(4) is bonded to one K(2), two equivalent K(1), and one Nb(1) atom to form a mixture of edge and corner-sharing FK3Nb tetrahedra. In the seventh F site, F(5) is bonded to one K(2), two equivalent K(1), and one Nb(1) atom to form a mixture of distorted edge and corner-sharing FK3Nb tetrahedra. is represented by the CIF file [CIF]
data_K2NbF7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.669
_cell_length_b   5.774
_cell_length_c   8.493
_cell_angle_alpha   90.034
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   621.299
_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  0.782  0.763  0.055  1.0
  K  K1  1  0.282  0.237  0.445  1.0
  K  K2  1  0.218  0.237  0.945  1.0
  K  K3  1  0.718  0.763  0.555  1.0
  K  K4  1  0.940  0.238  0.320  1.0
  K  K5  1  0.440  0.762  0.180  1.0
  K  K6  1  0.060  0.762  0.680  1.0
  K  K7  1  0.560  0.238  0.820  1.0
  Nb  Nb8  1  0.628  0.273  0.280  1.0
  Nb  Nb9  1  0.128  0.727  0.220  1.0
  Nb  Nb10  1  0.372  0.727  0.720  1.0
  Nb  Nb11  1  0.872  0.273  0.780  1.0
  F  F12  1  0.576  0.568  0.372  1.0
  F  F13  1  0.076  0.432  0.128  1.0
  F  F14  1  0.424  0.432  0.628  1.0
  F  F15  1  0.924  0.568  0.872  1.0
  F  F16  1  0.623  0.189  0.503  1.0
  F  F17  1  0.123  0.811  0.997  1.0
  F  F18  1  0.377  0.811  0.497  1.0
  F  F19  1  0.877  0.189  0.003  1.0
  F  F20  1  0.475  0.211  0.288  1.0
  F  F21  1  0.975  0.789  0.212  1.0
  F  F22  1  0.525  0.789  0.712  1.0
  F  F23  1  0.025  0.211  0.788  1.0
  F  F24  1  0.755  0.042  0.802  1.0
  F  F25  1  0.255  0.958  0.698  1.0
  F  F26  1  0.245  0.958  0.198  1.0
  F  F27  1  0.745  0.042  0.302  1.0
  F  F28  1  0.742  0.466  0.794  1.0
  F  F29  1  0.242  0.534  0.706  1.0
  F  F30  1  0.258  0.534  0.206  1.0
  F  F31  1  0.758  0.466  0.294  1.0
  F  F32  1  0.893  0.041  0.608  1.0
  F  F33  1  0.393  0.959  0.892  1.0
  F  F34  1  0.107  0.959  0.392  1.0
  F  F35  1  0.607  0.041  0.108  1.0
  F  F36  1  0.891  0.469  0.589  1.0
  F  F37  1  0.391  0.531  0.911  1.0
  F  F38  1  0.109  0.531  0.411  1.0
  F  F39  1  0.609  0.469  0.089  1.0
[/CIF]
.