The compound described by Na2SiF6 crystallizes in the trigonal P-3m1 space group. Na(1) is bonded to two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms to form distorted NaF6 octahedra that share corners with four equivalent Si(1)F6 octahedra,  an edgeedge with one Si(2)F6 octahedra, and edges with three equivalent Na(1)F6 octahedra. The corner-sharing octahedral tilt angles range from 40-44°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to three equivalent F(1) and three equivalent F(2) atoms to form SiF6 octahedra that share corners with twelve equivalent Na(1)F6 octahedra. The corner-sharing octahedral tilt angles range from 40-44°. In the second Si site, Si(2) is bonded to six equivalent F(3) atoms to form SiF6 octahedra that share edges with six equivalent Na(1)F6 octahedra. There are three inequivalent F sites. In the first F site, F(1) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one Si(1) atom. In the second F site, F(2) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one Si(1) atom. In the third F site, F(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Na(1) and one Si(2) atom. is represented by the CIF card [CIF]
data_Na2SiF6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.345
_cell_length_b   9.345
_cell_length_c   4.582
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   346.543
_cell_formula_units_Z   3
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
  Na  Na0  1  0.343  0.343  0.000  1.0
  Na  Na1  1  0.000  0.657  0.000  1.0
  Na  Na2  1  0.657  0.000  0.000  1.0
  Na  Na3  1  0.657  0.657  0.000  1.0
  Na  Na4  1  0.000  0.343  0.000  1.0
  Na  Na5  1  0.343  0.000  0.000  1.0
  Si  Si6  1  0.667  0.333  0.500  1.0
  Si  Si7  1  0.333  0.667  0.500  1.0
  Si  Si8  1  0.000  0.000  0.000  1.0
  F  F9  1  0.579  0.421  0.716  1.0
  F  F10  1  0.579  0.158  0.716  1.0
  F  F11  1  0.842  0.421  0.716  1.0
  F  F12  1  0.158  0.579  0.284  1.0
  F  F13  1  0.421  0.842  0.284  1.0
  F  F14  1  0.421  0.579  0.284  1.0
  F  F15  1  0.754  0.246  0.286  1.0
  F  F16  1  0.754  0.508  0.286  1.0
  F  F17  1  0.492  0.246  0.286  1.0
  F  F18  1  0.088  0.912  0.209  1.0
  F  F19  1  0.088  0.177  0.209  1.0
  F  F20  1  0.823  0.912  0.209  1.0
  F  F21  1  0.177  0.088  0.791  1.0
  F  F22  1  0.912  0.823  0.791  1.0
  F  F23  1  0.912  0.088  0.791  1.0
  F  F24  1  0.246  0.754  0.714  1.0
  F  F25  1  0.246  0.492  0.714  1.0
  F  F26  1  0.508  0.754  0.714  1.0
[/CIF]
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The compound described by Na2SiF6 crystallizes in the trigonal P-3m1 space group. Na(1) is bonded to two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms to form distorted NaF6 octahedra that share corners with four equivalent Si(1)F6 octahedra,  an edgeedge with one Si(2)F6 octahedra, and edges with three equivalent Na(1)F6 octahedra. The corner-sharing octahedral tilt angles range from 40-44°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to three equivalent F(1) and three equivalent F(2) atoms to form SiF6 octahedra that share corners with twelve equivalent Na(1)F6 octahedra. The corner-sharing octahedral tilt angles range from 40-44°. In the second Si site, Si(2) is bonded to six equivalent F(3) atoms to form SiF6 octahedra that share edges with six equivalent Na(1)F6 octahedra. There are three inequivalent F sites. In the first F site, F(1) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one Si(1) atom. In the second F site, F(2) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one Si(1) atom. In the third F site, F(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Na(1) and one Si(2) atom. is represented by the CIF card [CIF]
data_Na2SiF6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.345
_cell_length_b   9.345
_cell_length_c   4.582
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   346.543
_cell_formula_units_Z   3
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
  Na  Na0  1  0.343  0.343  0.000  1.0
  Na  Na1  1  0.000  0.657  0.000  1.0
  Na  Na2  1  0.657  0.000  0.000  1.0
  Na  Na3  1  0.657  0.657  0.000  1.0
  Na  Na4  1  0.000  0.343  0.000  1.0
  Na  Na5  1  0.343  0.000  0.000  1.0
  Si  Si6  1  0.667  0.333  0.500  1.0
  Si  Si7  1  0.333  0.667  0.500  1.0
  Si  Si8  1  0.000  0.000  0.000  1.0
  F  F9  1  0.579  0.421  0.716  1.0
  F  F10  1  0.579  0.158  0.716  1.0
  F  F11  1  0.842  0.421  0.716  1.0
  F  F12  1  0.158  0.579  0.284  1.0
  F  F13  1  0.421  0.842  0.284  1.0
  F  F14  1  0.421  0.579  0.284  1.0
  F  F15  1  0.754  0.246  0.286  1.0
  F  F16  1  0.754  0.508  0.286  1.0
  F  F17  1  0.492  0.246  0.286  1.0
  F  F18  1  0.088  0.912  0.209  1.0
  F  F19  1  0.088  0.177  0.209  1.0
  F  F20  1  0.823  0.912  0.209  1.0
  F  F21  1  0.177  0.088  0.791  1.0
  F  F22  1  0.912  0.823  0.791  1.0
  F  F23  1  0.912  0.088  0.791  1.0
  F  F24  1  0.246  0.754  0.714  1.0
  F  F25  1  0.246  0.492  0.714  1.0
  F  F26  1  0.508  0.754  0.714  1.0
[/CIF]
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