The compound described by NaSi2O5 crystallizes in the tetragonal I-4 space group. Na(1) is bonded in a 5-coordinate geometry to one O(2), one O(4), and three equivalent O(3) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form SiO5 trigonal bipyramids that share corners with two equivalent Si(2)O4 tetrahedra and corners with two equivalent Si(1)O5 trigonal bipyramids. In the second Si site, Si(2) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with two equivalent Si(2)O4 tetrahedra and corners with two equivalent Si(1)O5 trigonal bipyramids. There are five inequivalent O sites. In the first O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Na(1) and one Si(1) atom. In the second O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Si(1), and one Si(2) atom. In the third O site, O(5) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Si(2) atoms. In the fifth O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Si(1), and one Si(2) atom. is represented by the CIF card [CIF]
data_NaSi2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.706
_cell_length_b   8.706
_cell_length_c   8.706
_cell_angle_alpha   106.976
_cell_angle_beta   106.976
_cell_angle_gamma   114.585
_symmetry_Int_Tables_number   1
_cell_volume   504.866
_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
  Na  Na0  1  0.522  0.260  0.545  1.0
  Na  Na1  1  0.715  0.977  0.455  1.0
  Na  Na2  1  0.740  0.285  0.262  1.0
  Na  Na3  1  0.023  0.478  0.738  1.0
  Si  Si4  1  0.097  0.163  0.314  1.0
  Si  Si5  1  0.849  0.783  0.686  1.0
  Si  Si6  1  0.837  0.151  0.934  1.0
  Si  Si7  1  0.217  0.903  0.066  1.0
  Si  Si8  1  0.396  0.604  0.502  1.0
  Si  Si9  1  0.102  0.894  0.498  1.0
  Si  Si10  1  0.396  0.898  0.792  1.0
  Si  Si11  1  0.106  0.604  0.208  1.0
  O  O12  1  0.349  0.687  0.665  1.0
  O  O13  1  0.022  0.685  0.335  1.0
  O  O14  1  0.313  0.978  0.662  1.0
  O  O15  1  0.315  0.651  0.338  1.0
  O  O16  1  0.623  0.719  0.572  1.0
  O  O17  1  0.148  0.051  0.428  1.0
  O  O18  1  0.281  0.852  0.904  1.0
  O  O19  1  0.949  0.377  0.096  1.0
  O  O20  1  0.806  0.556  0.602  1.0
  O  O21  1  0.954  0.205  0.398  1.0
  O  O22  1  0.444  0.046  0.250  1.0
  O  O23  1  0.795  0.194  0.750  1.0
  O  O24  1  0.305  0.379  0.436  1.0
  O  O25  1  0.943  0.869  0.564  1.0
  O  O26  1  0.621  0.057  0.926  1.0
  O  O27  1  0.131  0.695  0.074  1.0
  O  O28  1  0.972  0.800  0.886  1.0
  O  O29  1  0.915  0.086  0.114  1.0
  O  O30  1  0.200  0.085  0.172  1.0
  O  O31  1  0.914  0.028  0.828  1.0
[/CIF]
.
The compound described by NaSi2O5 crystallizes in the tetragonal I-4 space group. Na(1) is bonded in a 5-coordinate geometry to one O(2), one O(4), and three equivalent O(3) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form SiO5 trigonal bipyramids that share corners with two equivalent Si(2)O4 tetrahedra and corners with two equivalent Si(1)O5 trigonal bipyramids. In the second Si site, Si(2) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with two equivalent Si(2)O4 tetrahedra and corners with two equivalent Si(1)O5 trigonal bipyramids. There are five inequivalent O sites. In the first O site, O(3) is bonded in a 4-coordinate geometry to three equivalent Na(1) and one Si(1) atom. In the second O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Si(1), and one Si(2) atom. In the third O site, O(5) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Si(2) atoms. In the fifth O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Si(1), and one Si(2) atom. is represented by the CIF card [CIF]
data_NaSi2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.706
_cell_length_b   8.706
_cell_length_c   8.706
_cell_angle_alpha   106.976
_cell_angle_beta   106.976
_cell_angle_gamma   114.585
_symmetry_Int_Tables_number   1
_cell_volume   504.866
_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
  Na  Na0  1  0.522  0.260  0.545  1.0
  Na  Na1  1  0.715  0.977  0.455  1.0
  Na  Na2  1  0.740  0.285  0.262  1.0
  Na  Na3  1  0.023  0.478  0.738  1.0
  Si  Si4  1  0.097  0.163  0.314  1.0
  Si  Si5  1  0.849  0.783  0.686  1.0
  Si  Si6  1  0.837  0.151  0.934  1.0
  Si  Si7  1  0.217  0.903  0.066  1.0
  Si  Si8  1  0.396  0.604  0.502  1.0
  Si  Si9  1  0.102  0.894  0.498  1.0
  Si  Si10  1  0.396  0.898  0.792  1.0
  Si  Si11  1  0.106  0.604  0.208  1.0
  O  O12  1  0.349  0.687  0.665  1.0
  O  O13  1  0.022  0.685  0.335  1.0
  O  O14  1  0.313  0.978  0.662  1.0
  O  O15  1  0.315  0.651  0.338  1.0
  O  O16  1  0.623  0.719  0.572  1.0
  O  O17  1  0.148  0.051  0.428  1.0
  O  O18  1  0.281  0.852  0.904  1.0
  O  O19  1  0.949  0.377  0.096  1.0
  O  O20  1  0.806  0.556  0.602  1.0
  O  O21  1  0.954  0.205  0.398  1.0
  O  O22  1  0.444  0.046  0.250  1.0
  O  O23  1  0.795  0.194  0.750  1.0
  O  O24  1  0.305  0.379  0.436  1.0
  O  O25  1  0.943  0.869  0.564  1.0
  O  O26  1  0.621  0.057  0.926  1.0
  O  O27  1  0.131  0.695  0.074  1.0
  O  O28  1  0.972  0.800  0.886  1.0
  O  O29  1  0.915  0.086  0.114  1.0
  O  O30  1  0.200  0.085  0.172  1.0
  O  O31  1  0.914  0.028  0.828  1.0
[/CIF]
.