The material described by NaVSi2O6 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Na(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. V(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form VO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent V(1)O6 octahedra. Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form SiO4 tetrahedra that share corners with three equivalent V(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 32-59°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), two equivalent V(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Na(1), one V(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Na(1) and two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_NaV(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.382
_cell_length_b   6.610
_cell_length_c   6.610
_cell_angle_alpha   84.246
_cell_angle_beta   77.457
_cell_angle_gamma   77.449
_symmetry_Int_Tables_number   1
_cell_volume   223.715
_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
  Na  Na0  1  0.250  0.299  0.701  1.0
  Na  Na1  1  0.750  0.701  0.299  1.0
  O  O2  1  0.352  0.196  0.037  1.0
  O  O3  1  0.648  0.804  0.963  1.0
  O  O4  1  0.852  0.037  0.196  1.0
  O  O5  1  0.148  0.963  0.803  1.0
  O  O6  1  0.307  0.892  0.382  1.0
  O  O7  1  0.693  0.108  0.618  1.0
  O  O8  1  0.193  0.618  0.108  1.0
  O  O9  1  0.807  0.382  0.892  1.0
  O  O10  1  0.019  0.655  0.642  1.0
  O  O11  1  0.481  0.358  0.345  1.0
  O  O12  1  0.519  0.642  0.655  1.0
  O  O13  1  0.981  0.345  0.358  1.0
  Si  Si14  1  0.743  0.618  0.798  1.0
  Si  Si15  1  0.243  0.798  0.618  1.0
  Si  Si16  1  0.757  0.202  0.382  1.0
  Si  Si17  1  0.257  0.382  0.202  1.0
  V  V18  1  0.250  0.906  0.094  1.0
  V  V19  1  0.750  0.094  0.906  1.0
[/CIF]
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The material described by NaVSi2O6 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Na(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. V(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form VO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent V(1)O6 octahedra. Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form SiO4 tetrahedra that share corners with three equivalent V(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 32-59°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), two equivalent V(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Na(1), one V(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Na(1) and two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_NaV(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.382
_cell_length_b   6.610
_cell_length_c   6.610
_cell_angle_alpha   84.246
_cell_angle_beta   77.457
_cell_angle_gamma   77.449
_symmetry_Int_Tables_number   1
_cell_volume   223.715
_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
  Na  Na0  1  0.250  0.299  0.701  1.0
  Na  Na1  1  0.750  0.701  0.299  1.0
  O  O2  1  0.352  0.196  0.037  1.0
  O  O3  1  0.648  0.804  0.963  1.0
  O  O4  1  0.852  0.037  0.196  1.0
  O  O5  1  0.148  0.963  0.803  1.0
  O  O6  1  0.307  0.892  0.382  1.0
  O  O7  1  0.693  0.108  0.618  1.0
  O  O8  1  0.193  0.618  0.108  1.0
  O  O9  1  0.807  0.382  0.892  1.0
  O  O10  1  0.019  0.655  0.642  1.0
  O  O11  1  0.481  0.358  0.345  1.0
  O  O12  1  0.519  0.642  0.655  1.0
  O  O13  1  0.981  0.345  0.358  1.0
  Si  Si14  1  0.743  0.618  0.798  1.0
  Si  Si15  1  0.243  0.798  0.618  1.0
  Si  Si16  1  0.757  0.202  0.382  1.0
  Si  Si17  1  0.257  0.382  0.202  1.0
  V  V18  1  0.250  0.906  0.094  1.0
  V  V19  1  0.750  0.094  0.906  1.0
[/CIF]
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