The material described by K3Nb3Si2O13 is Pb(Zr_(1-x)Ti_x)O3-derived structured and crystallizes in the hexagonal P-62c space group. K(1) is bonded in a 12-coordinate geometry to one O(4), two equivalent O(3), three equivalent O(2), and six equivalent O(1) atoms. Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with four equivalent Nb(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 9-30°. Si(1) is bonded to one O(4) and three equivalent O(1) atoms to form SiO4 tetrahedra that share corners with three equivalent Nb(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 24°. There are four inequivalent O sites. In the first O site, O(4) is bonded in a linear geometry to three equivalent K(1) and two equivalent Si(1) atoms. In the second O site, O(1) is bonded in a 2-coordinate geometry to three equivalent K(1), one Nb(1), and one Si(1) atom. In the third O site, O(2) is bonded in a linear geometry to three equivalent K(1) and two equivalent Nb(1) atoms. In the fourth O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1) and two equivalent Nb(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_K3Nb3Si2O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.247
_cell_length_b   9.247
_cell_length_c   7.966
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   589.873
_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  0.384  0.968  0.250  1.0
  K  K1  1  0.616  0.584  0.750  1.0
  K  K2  1  0.032  0.416  0.250  1.0
  K  K3  1  0.584  0.616  0.250  1.0
  K  K4  1  0.416  0.032  0.750  1.0
  K  K5  1  0.968  0.384  0.750  1.0
  Nb  Nb6  1  0.762  0.000  0.500  1.0
  Nb  Nb7  1  0.762  0.000  0.000  1.0
  Nb  Nb8  1  0.238  0.238  0.000  1.0
  Nb  Nb9  1  0.238  0.238  0.500  1.0
  Nb  Nb10  1  0.000  0.762  0.500  1.0
  Nb  Nb11  1  0.000  0.762  0.000  1.0
  Si  Si12  1  0.333  0.667  0.955  1.0
  Si  Si13  1  0.667  0.333  0.045  1.0
  Si  Si14  1  0.667  0.333  0.455  1.0
  Si  Si15  1  0.333  0.667  0.545  1.0
  O  O16  1  0.488  0.307  0.980  1.0
  O  O17  1  0.989  0.743  0.250  1.0
  O  O18  1  0.011  0.754  0.750  1.0
  O  O19  1  0.743  0.989  0.750  1.0
  O  O20  1  0.754  0.011  0.250  1.0
  O  O21  1  0.512  0.819  0.480  1.0
  O  O22  1  0.181  0.693  0.020  1.0
  O  O23  1  0.246  0.257  0.750  1.0
  O  O24  1  0.819  0.512  0.980  1.0
  O  O25  1  0.693  0.181  0.520  1.0
  O  O26  1  0.825  0.825  0.500  1.0
  O  O27  1  0.825  0.825  0.000  1.0
  O  O28  1  0.693  0.181  0.980  1.0
  O  O29  1  0.257  0.246  0.250  1.0
  O  O30  1  0.819  0.512  0.520  1.0
  O  O31  1  0.307  0.488  0.020  1.0
  O  O32  1  0.512  0.819  0.020  1.0
  O  O33  1  0.307  0.488  0.480  1.0
  O  O34  1  0.175  0.000  0.500  1.0
  O  O35  1  0.181  0.693  0.480  1.0
  O  O36  1  0.667  0.333  0.250  1.0
  O  O37  1  0.000  0.175  0.500  1.0
  O  O38  1  0.488  0.307  0.520  1.0
  O  O39  1  0.000  0.175  0.000  1.0
  O  O40  1  0.175  0.000  0.000  1.0
  O  O41  1  0.333  0.667  0.750  1.0
[/CIF]
.
The material described by K3Nb3Si2O13 is Pb(Zr_(1-x)Ti_x)O3-derived structured and crystallizes in the hexagonal P-62c space group. K(1) is bonded in a 12-coordinate geometry to one O(4), two equivalent O(3), three equivalent O(2), and six equivalent O(1) atoms. Nb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form NbO6 octahedra that share corners with four equivalent Nb(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 9-30°. Si(1) is bonded to one O(4) and three equivalent O(1) atoms to form SiO4 tetrahedra that share corners with three equivalent Nb(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 24°. There are four inequivalent O sites. In the first O site, O(4) is bonded in a linear geometry to three equivalent K(1) and two equivalent Si(1) atoms. In the second O site, O(1) is bonded in a 2-coordinate geometry to three equivalent K(1), one Nb(1), and one Si(1) atom. In the third O site, O(2) is bonded in a linear geometry to three equivalent K(1) and two equivalent Nb(1) atoms. In the fourth O site, O(3) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1) and two equivalent Nb(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_K3Nb3Si2O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.247
_cell_length_b   9.247
_cell_length_c   7.966
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   589.873
_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  0.384  0.968  0.250  1.0
  K  K1  1  0.616  0.584  0.750  1.0
  K  K2  1  0.032  0.416  0.250  1.0
  K  K3  1  0.584  0.616  0.250  1.0
  K  K4  1  0.416  0.032  0.750  1.0
  K  K5  1  0.968  0.384  0.750  1.0
  Nb  Nb6  1  0.762  0.000  0.500  1.0
  Nb  Nb7  1  0.762  0.000  0.000  1.0
  Nb  Nb8  1  0.238  0.238  0.000  1.0
  Nb  Nb9  1  0.238  0.238  0.500  1.0
  Nb  Nb10  1  0.000  0.762  0.500  1.0
  Nb  Nb11  1  0.000  0.762  0.000  1.0
  Si  Si12  1  0.333  0.667  0.955  1.0
  Si  Si13  1  0.667  0.333  0.045  1.0
  Si  Si14  1  0.667  0.333  0.455  1.0
  Si  Si15  1  0.333  0.667  0.545  1.0
  O  O16  1  0.488  0.307  0.980  1.0
  O  O17  1  0.989  0.743  0.250  1.0
  O  O18  1  0.011  0.754  0.750  1.0
  O  O19  1  0.743  0.989  0.750  1.0
  O  O20  1  0.754  0.011  0.250  1.0
  O  O21  1  0.512  0.819  0.480  1.0
  O  O22  1  0.181  0.693  0.020  1.0
  O  O23  1  0.246  0.257  0.750  1.0
  O  O24  1  0.819  0.512  0.980  1.0
  O  O25  1  0.693  0.181  0.520  1.0
  O  O26  1  0.825  0.825  0.500  1.0
  O  O27  1  0.825  0.825  0.000  1.0
  O  O28  1  0.693  0.181  0.980  1.0
  O  O29  1  0.257  0.246  0.250  1.0
  O  O30  1  0.819  0.512  0.520  1.0
  O  O31  1  0.307  0.488  0.020  1.0
  O  O32  1  0.512  0.819  0.020  1.0
  O  O33  1  0.307  0.488  0.480  1.0
  O  O34  1  0.175  0.000  0.500  1.0
  O  O35  1  0.181  0.693  0.480  1.0
  O  O36  1  0.667  0.333  0.250  1.0
  O  O37  1  0.000  0.175  0.500  1.0
  O  O38  1  0.488  0.307  0.520  1.0
  O  O39  1  0.000  0.175  0.000  1.0
  O  O40  1  0.175  0.000  0.000  1.0
  O  O41  1  0.333  0.667  0.750  1.0
[/CIF]
.