The structure described by KNa2Y(Si2O5)3 crystallizes in the orthorhombic Imma space group. K(1) is bonded in a 10-coordinate geometry to two equivalent O(5), four equivalent O(1), and four equivalent O(4) atoms. Na(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Y(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form YO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra and corners with four equivalent Si(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Y(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. In the second Si site, Si(2) is bonded to one O(3), one O(6), and two equivalent O(2) atoms to form SiO4 tetrahedra that share  a cornercorner with one Y(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 18°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Na(1), one Y(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Si(1), and one Si(2) atom. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to two equivalent Na(1), one Y(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1) and two equivalent Si(1) atoms. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one K(1) and two equivalent Si(1) atoms. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to two equivalent Si(2) atoms. is represented by the CIF card [CIF]
data_KNa2Y(Si2O5)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.240
_cell_length_b   10.240
_cell_length_c   10.240
_cell_angle_alpha   130.012
_cell_angle_beta   116.676
_cell_angle_gamma   84.727
_symmetry_Int_Tables_number   1
_cell_volume   703.903
_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  0.430  0.250  0.180  1.0
  K  K1  1  0.570  0.750  0.820  1.0
  Na  Na2  1  0.757  0.757  0.500  1.0
  Na  Na3  1  0.243  0.243  0.500  1.0
  Na  Na4  1  0.757  0.257  0.000  1.0
  Na  Na5  1  0.243  0.743  0.000  1.0
  Y  Y6  1  0.500  0.500  0.000  1.0
  Y  Y7  1  0.000  0.000  0.000  1.0
  Si  Si8  1  0.384  0.026  0.702  1.0
  Si  Si9  1  0.066  0.350  0.716  1.0
  Si  Si10  1  0.176  0.818  0.702  1.0
  Si  Si11  1  0.134  0.850  0.284  1.0
  Si  Si12  1  0.866  0.150  0.716  1.0
  Si  Si13  1  0.616  0.318  0.642  1.0
  Si  Si14  1  0.616  0.974  0.298  1.0
  Si  Si15  1  0.934  0.650  0.284  1.0
  Si  Si16  1  0.824  0.526  0.642  1.0
  Si  Si17  1  0.824  0.182  0.298  1.0
  Si  Si18  1  0.384  0.682  0.358  1.0
  Si  Si19  1  0.176  0.474  0.358  1.0
  O  O20  1  0.830  0.723  0.726  1.0
  O  O21  1  0.238  0.014  0.530  1.0
  O  O22  1  0.170  0.277  0.274  1.0
  O  O23  1  0.756  0.573  0.183  1.0
  O  O24  1  0.238  0.709  0.225  1.0
  O  O25  1  0.503  0.395  0.726  1.0
  O  O26  1  0.319  0.956  0.775  1.0
  O  O27  1  0.503  0.777  0.108  1.0
  O  O28  1  0.889  0.073  0.817  1.0
  O  O29  1  0.016  0.486  0.225  1.0
  O  O30  1  0.681  0.044  0.225  1.0
  O  O31  1  0.244  0.427  0.817  1.0
  O  O32  1  0.830  0.105  0.108  1.0
  O  O33  1  0.762  0.291  0.775  1.0
  O  O34  1  0.497  0.605  0.274  1.0
  O  O35  1  0.530  0.121  0.409  1.0
  O  O36  1  0.762  0.986  0.470  1.0
  O  O37  1  0.212  0.621  0.591  1.0
  O  O38  1  0.497  0.223  0.892  1.0
  O  O39  1  0.681  0.456  0.637  1.0
  O  O40  1  0.025  0.250  0.775  1.0
  O  O41  1  0.170  0.895  0.892  1.0
  O  O42  1  0.319  0.544  0.363  1.0
  O  O43  1  0.975  0.750  0.225  1.0
  O  O44  1  0.984  0.209  0.470  1.0
  O  O45  1  0.016  0.791  0.530  1.0
  O  O46  1  0.984  0.514  0.775  1.0
  O  O47  1  0.788  0.379  0.409  1.0
  O  O48  1  0.111  0.927  0.183  1.0
  O  O49  1  0.470  0.879  0.591  1.0
[/CIF]
.
The structure described by KNa2Y(Si2O5)3 crystallizes in the orthorhombic Imma space group. K(1) is bonded in a 10-coordinate geometry to two equivalent O(5), four equivalent O(1), and four equivalent O(4) atoms. Na(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Y(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form YO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra and corners with four equivalent Si(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Y(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. In the second Si site, Si(2) is bonded to one O(3), one O(6), and two equivalent O(2) atoms to form SiO4 tetrahedra that share  a cornercorner with one Y(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 18°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Na(1), one Y(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Si(1), and one Si(2) atom. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to two equivalent Na(1), one Y(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1) and two equivalent Si(1) atoms. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one K(1) and two equivalent Si(1) atoms. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to two equivalent Si(2) atoms. is represented by the CIF card [CIF]
data_KNa2Y(Si2O5)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.240
_cell_length_b   10.240
_cell_length_c   10.240
_cell_angle_alpha   130.012
_cell_angle_beta   116.676
_cell_angle_gamma   84.727
_symmetry_Int_Tables_number   1
_cell_volume   703.903
_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  0.430  0.250  0.180  1.0
  K  K1  1  0.570  0.750  0.820  1.0
  Na  Na2  1  0.757  0.757  0.500  1.0
  Na  Na3  1  0.243  0.243  0.500  1.0
  Na  Na4  1  0.757  0.257  0.000  1.0
  Na  Na5  1  0.243  0.743  0.000  1.0
  Y  Y6  1  0.500  0.500  0.000  1.0
  Y  Y7  1  0.000  0.000  0.000  1.0
  Si  Si8  1  0.384  0.026  0.702  1.0
  Si  Si9  1  0.066  0.350  0.716  1.0
  Si  Si10  1  0.176  0.818  0.702  1.0
  Si  Si11  1  0.134  0.850  0.284  1.0
  Si  Si12  1  0.866  0.150  0.716  1.0
  Si  Si13  1  0.616  0.318  0.642  1.0
  Si  Si14  1  0.616  0.974  0.298  1.0
  Si  Si15  1  0.934  0.650  0.284  1.0
  Si  Si16  1  0.824  0.526  0.642  1.0
  Si  Si17  1  0.824  0.182  0.298  1.0
  Si  Si18  1  0.384  0.682  0.358  1.0
  Si  Si19  1  0.176  0.474  0.358  1.0
  O  O20  1  0.830  0.723  0.726  1.0
  O  O21  1  0.238  0.014  0.530  1.0
  O  O22  1  0.170  0.277  0.274  1.0
  O  O23  1  0.756  0.573  0.183  1.0
  O  O24  1  0.238  0.709  0.225  1.0
  O  O25  1  0.503  0.395  0.726  1.0
  O  O26  1  0.319  0.956  0.775  1.0
  O  O27  1  0.503  0.777  0.108  1.0
  O  O28  1  0.889  0.073  0.817  1.0
  O  O29  1  0.016  0.486  0.225  1.0
  O  O30  1  0.681  0.044  0.225  1.0
  O  O31  1  0.244  0.427  0.817  1.0
  O  O32  1  0.830  0.105  0.108  1.0
  O  O33  1  0.762  0.291  0.775  1.0
  O  O34  1  0.497  0.605  0.274  1.0
  O  O35  1  0.530  0.121  0.409  1.0
  O  O36  1  0.762  0.986  0.470  1.0
  O  O37  1  0.212  0.621  0.591  1.0
  O  O38  1  0.497  0.223  0.892  1.0
  O  O39  1  0.681  0.456  0.637  1.0
  O  O40  1  0.025  0.250  0.775  1.0
  O  O41  1  0.170  0.895  0.892  1.0
  O  O42  1  0.319  0.544  0.363  1.0
  O  O43  1  0.975  0.750  0.225  1.0
  O  O44  1  0.984  0.209  0.470  1.0
  O  O45  1  0.016  0.791  0.530  1.0
  O  O46  1  0.984  0.514  0.775  1.0
  O  O47  1  0.788  0.379  0.409  1.0
  O  O48  1  0.111  0.927  0.183  1.0
  O  O49  1  0.470  0.879  0.591  1.0
[/CIF]
.