The material described by Si2N2O is beta indium sulfide-derived structured and crystallizes in the trigonal P-3m1 space group. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one N(2), one N(4), two equivalent N(1), and two equivalent O(2) atoms to form SiN4O2 octahedra that share  a cornercorner with one Si(5)N4 tetrahedra, corners with three equivalent Si(6)N4 tetrahedra,  an edgeedge with one Si(4)N3O3 octahedra,  an edgeedge with one Si(3)N6 octahedra, and edges with four equivalent Si(1)N4O2 octahedra. In the second Si site, Si(2) is bonded to four equivalent N(3) and two equivalent O(1) atoms to form SiN4O2 octahedra that share corners with four equivalent Si(5)N4 tetrahedra, edges with two equivalent Si(4)N3O3 octahedra, and edges with four equivalent Si(2)N4O2 octahedra. In the third Si site, Si(3) is bonded to six equivalent N(1) atoms to form SiN6 octahedra that share corners with six equivalent Si(6)N4 tetrahedra and edges with six equivalent Si(1)N4O2 octahedra. In the fourth Si site, Si(4) is bonded to three equivalent N(3) and three equivalent O(2) atoms to form SiN3O3 octahedra that share corners with three equivalent Si(5)N4 tetrahedra, edges with three equivalent Si(1)N4O2 octahedra, and edges with three equivalent Si(2)N4O2 octahedra. In the fifth Si site, Si(5) is bonded to one N(4) and three equivalent N(3) atoms to form SiN4 tetrahedra that share corners with three equivalent Si(4)N3O3 octahedra, corners with three equivalent Si(1)N4O2 octahedra, and corners with six equivalent Si(2)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the sixth Si site, Si(6) is bonded to one N(2) and three equivalent N(1) atoms to form SiN4 tetrahedra that share corners with three equivalent Si(3)N6 octahedra and corners with nine equivalent Si(1)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 56-58°. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Si(3), one Si(6), and two equivalent Si(1) atoms to form a mixture of distorted edge and corner-sharing NSi4 trigonal pyramids. In the second N site, N(2) is bonded in a rectangular see-saw-like geometry to one Si(6) and three equivalent Si(1) atoms. In the third N site, N(3) is bonded in a distorted rectangular see-saw-like geometry to one Si(4), one Si(5), and two equivalent Si(2) atoms. In the fourth N site, N(4) is bonded to one Si(5) and three equivalent Si(1) atoms to form distorted edge-sharing NSi4 trigonal pyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Si(2) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Si(4) and two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_Si2N2O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.493
_cell_length_b   5.493
_cell_length_c   13.479
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   352.181
_cell_formula_units_Z   8
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
  Si  Si0  1  0.832  0.168  0.835  1.0
  Si  Si1  1  0.663  0.832  0.165  1.0
  Si  Si2  1  0.168  0.832  0.165  1.0
  Si  Si3  1  0.337  0.168  0.835  1.0
  Si  Si4  1  0.168  0.337  0.165  1.0
  Si  Si5  1  0.832  0.663  0.835  1.0
  Si  Si6  1  0.500  0.500  0.500  1.0
  Si  Si7  1  0.000  0.500  0.500  1.0
  Si  Si8  1  0.500  0.000  0.500  1.0
  Si  Si9  1  0.000  0.000  0.000  1.0
  Si  Si10  1  0.333  0.667  0.330  1.0
  Si  Si11  1  0.667  0.333  0.670  1.0
  Si  Si12  1  0.000  0.000  0.371  1.0
  Si  Si13  1  0.000  0.000  0.629  1.0
  Si  Si14  1  0.667  0.333  0.045  1.0
  Si  Si15  1  0.333  0.667  0.955  1.0
  N  N16  1  0.686  0.843  0.913  1.0
  N  N17  1  0.314  0.157  0.087  1.0
  N  N18  1  0.843  0.157  0.087  1.0
  N  N19  1  0.157  0.843  0.913  1.0
  N  N20  1  0.843  0.686  0.087  1.0
  N  N21  1  0.157  0.314  0.913  1.0
  N  N22  1  0.333  0.667  0.087  1.0
  N  N23  1  0.667  0.333  0.913  1.0
  N  N24  1  0.176  0.352  0.416  1.0
  N  N25  1  0.824  0.648  0.584  1.0
  N  N26  1  0.824  0.176  0.584  1.0
  N  N27  1  0.648  0.824  0.416  1.0
  N  N28  1  0.176  0.824  0.416  1.0
  N  N29  1  0.352  0.176  0.584  1.0
  N  N30  1  0.000  0.000  0.241  1.0
  N  N31  1  0.000  0.000  0.759  1.0
  O  O32  1  0.333  0.667  0.563  1.0
  O  O33  1  0.667  0.333  0.437  1.0
  O  O34  1  0.521  0.479  0.758  1.0
  O  O35  1  0.043  0.521  0.242  1.0
  O  O36  1  0.479  0.957  0.242  1.0
  O  O37  1  0.957  0.479  0.758  1.0
  O  O38  1  0.521  0.043  0.758  1.0
  O  O39  1  0.479  0.521  0.242  1.0
[/CIF]
.
The material described by Si2N2O is beta indium sulfide-derived structured and crystallizes in the trigonal P-3m1 space group. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one N(2), one N(4), two equivalent N(1), and two equivalent O(2) atoms to form SiN4O2 octahedra that share  a cornercorner with one Si(5)N4 tetrahedra, corners with three equivalent Si(6)N4 tetrahedra,  an edgeedge with one Si(4)N3O3 octahedra,  an edgeedge with one Si(3)N6 octahedra, and edges with four equivalent Si(1)N4O2 octahedra. In the second Si site, Si(2) is bonded to four equivalent N(3) and two equivalent O(1) atoms to form SiN4O2 octahedra that share corners with four equivalent Si(5)N4 tetrahedra, edges with two equivalent Si(4)N3O3 octahedra, and edges with four equivalent Si(2)N4O2 octahedra. In the third Si site, Si(3) is bonded to six equivalent N(1) atoms to form SiN6 octahedra that share corners with six equivalent Si(6)N4 tetrahedra and edges with six equivalent Si(1)N4O2 octahedra. In the fourth Si site, Si(4) is bonded to three equivalent N(3) and three equivalent O(2) atoms to form SiN3O3 octahedra that share corners with three equivalent Si(5)N4 tetrahedra, edges with three equivalent Si(1)N4O2 octahedra, and edges with three equivalent Si(2)N4O2 octahedra. In the fifth Si site, Si(5) is bonded to one N(4) and three equivalent N(3) atoms to form SiN4 tetrahedra that share corners with three equivalent Si(4)N3O3 octahedra, corners with three equivalent Si(1)N4O2 octahedra, and corners with six equivalent Si(2)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the sixth Si site, Si(6) is bonded to one N(2) and three equivalent N(1) atoms to form SiN4 tetrahedra that share corners with three equivalent Si(3)N6 octahedra and corners with nine equivalent Si(1)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 56-58°. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Si(3), one Si(6), and two equivalent Si(1) atoms to form a mixture of distorted edge and corner-sharing NSi4 trigonal pyramids. In the second N site, N(2) is bonded in a rectangular see-saw-like geometry to one Si(6) and three equivalent Si(1) atoms. In the third N site, N(3) is bonded in a distorted rectangular see-saw-like geometry to one Si(4), one Si(5), and two equivalent Si(2) atoms. In the fourth N site, N(4) is bonded to one Si(5) and three equivalent Si(1) atoms to form distorted edge-sharing NSi4 trigonal pyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Si(2) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Si(4) and two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_Si2N2O
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.493
_cell_length_b   5.493
_cell_length_c   13.479
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   352.181
_cell_formula_units_Z   8
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
  Si  Si0  1  0.832  0.168  0.835  1.0
  Si  Si1  1  0.663  0.832  0.165  1.0
  Si  Si2  1  0.168  0.832  0.165  1.0
  Si  Si3  1  0.337  0.168  0.835  1.0
  Si  Si4  1  0.168  0.337  0.165  1.0
  Si  Si5  1  0.832  0.663  0.835  1.0
  Si  Si6  1  0.500  0.500  0.500  1.0
  Si  Si7  1  0.000  0.500  0.500  1.0
  Si  Si8  1  0.500  0.000  0.500  1.0
  Si  Si9  1  0.000  0.000  0.000  1.0
  Si  Si10  1  0.333  0.667  0.330  1.0
  Si  Si11  1  0.667  0.333  0.670  1.0
  Si  Si12  1  0.000  0.000  0.371  1.0
  Si  Si13  1  0.000  0.000  0.629  1.0
  Si  Si14  1  0.667  0.333  0.045  1.0
  Si  Si15  1  0.333  0.667  0.955  1.0
  N  N16  1  0.686  0.843  0.913  1.0
  N  N17  1  0.314  0.157  0.087  1.0
  N  N18  1  0.843  0.157  0.087  1.0
  N  N19  1  0.157  0.843  0.913  1.0
  N  N20  1  0.843  0.686  0.087  1.0
  N  N21  1  0.157  0.314  0.913  1.0
  N  N22  1  0.333  0.667  0.087  1.0
  N  N23  1  0.667  0.333  0.913  1.0
  N  N24  1  0.176  0.352  0.416  1.0
  N  N25  1  0.824  0.648  0.584  1.0
  N  N26  1  0.824  0.176  0.584  1.0
  N  N27  1  0.648  0.824  0.416  1.0
  N  N28  1  0.176  0.824  0.416  1.0
  N  N29  1  0.352  0.176  0.584  1.0
  N  N30  1  0.000  0.000  0.241  1.0
  N  N31  1  0.000  0.000  0.759  1.0
  O  O32  1  0.333  0.667  0.563  1.0
  O  O33  1  0.667  0.333  0.437  1.0
  O  O34  1  0.521  0.479  0.758  1.0
  O  O35  1  0.043  0.521  0.242  1.0
  O  O36  1  0.479  0.957  0.242  1.0
  O  O37  1  0.957  0.479  0.758  1.0
  O  O38  1  0.521  0.043  0.758  1.0
  O  O39  1  0.479  0.521  0.242  1.0
[/CIF]
.