The material described by Na4Sr(SiO3)3 crystallizes in the monoclinic C2 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted NaO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra and corners with four equivalent Si(1)O4 tetrahedra. In the second Na site, Na(2) is bonded in a distorted bent 120 degrees geometry to two equivalent O(2) and two equivalent O(4) atoms. In the third Na site, Na(3) is bonded in a distorted bent 120 degrees geometry to one O(4) and two equivalent O(3) atoms. Sr(1) is bonded in a 9-coordinate geometry to one O(5), two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 40°. In the second Si site, Si(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 39°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one Sr(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Sr(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(3), one Sr(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Sr(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Sr(1) and two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_Na4Sr(SiO3)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.704
_cell_length_b   6.704
_cell_length_c   6.685
_cell_angle_alpha   70.537
_cell_angle_beta   70.537
_cell_angle_gamma   109.418
_symmetry_Int_Tables_number   1
_cell_volume   231.477
_cell_formula_units_Z   1
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  0.504  0.496  0.000  1.0
  Na  Na1  1  0.976  0.024  0.500  1.0
  Na  Na2  1  0.977  0.445  0.026  1.0
  Na  Na3  1  0.555  0.023  0.974  1.0
  Sr  Sr4  1  0.504  0.496  0.500  1.0
  Si  Si5  1  0.431  0.961  0.535  1.0
  Si  Si6  1  0.039  0.961  0.000  1.0
  Si  Si7  1  0.039  0.569  0.465  1.0
  O  O8  1  0.022  0.753  0.239  1.0
  O  O9  1  0.166  0.426  0.374  1.0
  O  O10  1  0.770  0.423  0.701  1.0
  O  O11  1  0.574  0.834  0.626  1.0
  O  O12  1  0.577  0.230  0.299  1.0
  O  O13  1  0.162  0.227  0.972  1.0
  O  O14  1  0.247  0.978  0.761  1.0
  O  O15  1  0.237  0.763  0.500  1.0
  O  O16  1  0.773  0.838  0.028  1.0
[/CIF]
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The material described by Na4Sr(SiO3)3 crystallizes in the monoclinic C2 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted NaO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra and corners with four equivalent Si(1)O4 tetrahedra. In the second Na site, Na(2) is bonded in a distorted bent 120 degrees geometry to two equivalent O(2) and two equivalent O(4) atoms. In the third Na site, Na(3) is bonded in a distorted bent 120 degrees geometry to one O(4) and two equivalent O(3) atoms. Sr(1) is bonded in a 9-coordinate geometry to one O(5), two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 40°. In the second Si site, Si(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form SiO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 39°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one Sr(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Sr(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(3), one Sr(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Sr(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a linear geometry to one Sr(1) and two equivalent Si(1) atoms. is represented by the CIF card [CIF]
data_Na4Sr(SiO3)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.704
_cell_length_b   6.704
_cell_length_c   6.685
_cell_angle_alpha   70.537
_cell_angle_beta   70.537
_cell_angle_gamma   109.418
_symmetry_Int_Tables_number   1
_cell_volume   231.477
_cell_formula_units_Z   1
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  0.504  0.496  0.000  1.0
  Na  Na1  1  0.976  0.024  0.500  1.0
  Na  Na2  1  0.977  0.445  0.026  1.0
  Na  Na3  1  0.555  0.023  0.974  1.0
  Sr  Sr4  1  0.504  0.496  0.500  1.0
  Si  Si5  1  0.431  0.961  0.535  1.0
  Si  Si6  1  0.039  0.961  0.000  1.0
  Si  Si7  1  0.039  0.569  0.465  1.0
  O  O8  1  0.022  0.753  0.239  1.0
  O  O9  1  0.166  0.426  0.374  1.0
  O  O10  1  0.770  0.423  0.701  1.0
  O  O11  1  0.574  0.834  0.626  1.0
  O  O12  1  0.577  0.230  0.299  1.0
  O  O13  1  0.162  0.227  0.972  1.0
  O  O14  1  0.247  0.978  0.761  1.0
  O  O15  1  0.237  0.763  0.500  1.0
  O  O16  1  0.773  0.838  0.028  1.0
[/CIF]
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