The crystal structure described by NaKSi2O5 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 6-coordinate geometry to one O(3), one O(5), two equivalent O(2), and two equivalent O(4) atoms. Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(5), and three equivalent O(3) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form corner-sharing SiO4 tetrahedra. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent K(1), one Na(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one K(1), three equivalent Na(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent K(1), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one K(1), one Na(1), one Si(1), and one Si(2) atom. is represented by the CIF card [CIF]
data_KNaSi2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.762
_cell_length_b   4.913
_cell_length_c   7.584
_cell_angle_alpha   88.744
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   512.682
_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  0.201  0.801  0.288  1.0
  K  K1  1  0.799  0.199  0.712  1.0
  K  K2  1  0.701  0.199  0.212  1.0
  K  K3  1  0.299  0.801  0.788  1.0
  Na  Na4  1  0.594  0.723  0.972  1.0
  Na  Na5  1  0.406  0.277  0.028  1.0
  Na  Na6  1  0.906  0.723  0.472  1.0
  Na  Na7  1  0.094  0.277  0.528  1.0
  Si  Si8  1  0.951  0.198  0.216  1.0
  Si  Si9  1  0.549  0.198  0.716  1.0
  Si  Si10  1  0.049  0.802  0.784  1.0
  Si  Si11  1  0.630  0.704  0.515  1.0
  Si  Si12  1  0.870  0.704  0.015  1.0
  Si  Si13  1  0.451  0.802  0.284  1.0
  Si  Si14  1  0.370  0.296  0.485  1.0
  Si  Si15  1  0.130  0.296  0.985  1.0
  O  O16  1  0.430  0.125  0.333  1.0
  O  O17  1  0.759  0.781  0.992  1.0
  O  O18  1  0.927  0.251  0.417  1.0
  O  O19  1  0.570  0.875  0.667  1.0
  O  O20  1  0.115  0.623  0.929  1.0
  O  O21  1  0.070  0.125  0.833  1.0
  O  O22  1  0.569  0.748  0.324  1.0
  O  O23  1  0.573  0.251  0.917  1.0
  O  O24  1  0.241  0.219  0.008  1.0
  O  O25  1  0.427  0.749  0.083  1.0
  O  O26  1  0.069  0.252  0.176  1.0
  O  O27  1  0.385  0.623  0.429  1.0
  O  O28  1  0.885  0.377  0.071  1.0
  O  O29  1  0.259  0.219  0.508  1.0
  O  O30  1  0.615  0.377  0.571  1.0
  O  O31  1  0.073  0.749  0.583  1.0
  O  O32  1  0.741  0.781  0.492  1.0
  O  O33  1  0.431  0.252  0.676  1.0
  O  O34  1  0.930  0.875  0.167  1.0
  O  O35  1  0.931  0.748  0.824  1.0
[/CIF]
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The crystal structure described by NaKSi2O5 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 6-coordinate geometry to one O(3), one O(5), two equivalent O(2), and two equivalent O(4) atoms. Na(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(5), and three equivalent O(3) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form corner-sharing SiO4 tetrahedra. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent K(1), one Na(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one K(1), three equivalent Na(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent K(1), one Si(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one K(1), one Na(1), one Si(1), and one Si(2) atom. is represented by the CIF card [CIF]
data_KNaSi2O5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   13.762
_cell_length_b   4.913
_cell_length_c   7.584
_cell_angle_alpha   88.744
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   512.682
_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  0.201  0.801  0.288  1.0
  K  K1  1  0.799  0.199  0.712  1.0
  K  K2  1  0.701  0.199  0.212  1.0
  K  K3  1  0.299  0.801  0.788  1.0
  Na  Na4  1  0.594  0.723  0.972  1.0
  Na  Na5  1  0.406  0.277  0.028  1.0
  Na  Na6  1  0.906  0.723  0.472  1.0
  Na  Na7  1  0.094  0.277  0.528  1.0
  Si  Si8  1  0.951  0.198  0.216  1.0
  Si  Si9  1  0.549  0.198  0.716  1.0
  Si  Si10  1  0.049  0.802  0.784  1.0
  Si  Si11  1  0.630  0.704  0.515  1.0
  Si  Si12  1  0.870  0.704  0.015  1.0
  Si  Si13  1  0.451  0.802  0.284  1.0
  Si  Si14  1  0.370  0.296  0.485  1.0
  Si  Si15  1  0.130  0.296  0.985  1.0
  O  O16  1  0.430  0.125  0.333  1.0
  O  O17  1  0.759  0.781  0.992  1.0
  O  O18  1  0.927  0.251  0.417  1.0
  O  O19  1  0.570  0.875  0.667  1.0
  O  O20  1  0.115  0.623  0.929  1.0
  O  O21  1  0.070  0.125  0.833  1.0
  O  O22  1  0.569  0.748  0.324  1.0
  O  O23  1  0.573  0.251  0.917  1.0
  O  O24  1  0.241  0.219  0.008  1.0
  O  O25  1  0.427  0.749  0.083  1.0
  O  O26  1  0.069  0.252  0.176  1.0
  O  O27  1  0.385  0.623  0.429  1.0
  O  O28  1  0.885  0.377  0.071  1.0
  O  O29  1  0.259  0.219  0.508  1.0
  O  O30  1  0.615  0.377  0.571  1.0
  O  O31  1  0.073  0.749  0.583  1.0
  O  O32  1  0.741  0.781  0.492  1.0
  O  O33  1  0.431  0.252  0.676  1.0
  O  O34  1  0.930  0.875  0.167  1.0
  O  O35  1  0.931  0.748  0.824  1.0
[/CIF]
.