The material described by Si3N4 crystallizes in the hexagonal P6_3/m space group. Si(1) is bonded to one N(1) and three equivalent N(2) atoms to form corner-sharing SiN4 tetrahedra. There are two inequivalent N sites. In the first N site, N(2) is bonded in a trigonal planar geometry to three equivalent Si(1) atoms. In the second N site, N(1) is bonded in a trigonal planar geometry to three equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_Si3N4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.605
_cell_length_b   7.605
_cell_length_c   2.905
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   145.497
_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
  Si  Si0  1  0.231  0.825  0.750  1.0
  Si  Si1  1  0.406  0.231  0.250  1.0
  Si  Si2  1  0.825  0.594  0.250  1.0
  Si  Si3  1  0.175  0.406  0.750  1.0
  Si  Si4  1  0.594  0.769  0.750  1.0
  Si  Si5  1  0.769  0.175  0.250  1.0
  N  N6  1  0.333  0.667  0.750  1.0
  N  N7  1  0.667  0.333  0.250  1.0
  N  N8  1  0.969  0.670  0.750  1.0
  N  N9  1  0.299  0.969  0.250  1.0
  N  N10  1  0.670  0.701  0.250  1.0
  N  N11  1  0.330  0.299  0.750  1.0
  N  N12  1  0.031  0.330  0.250  1.0
  N  N13  1  0.701  0.031  0.750  1.0
[/CIF]
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The material described by Si3N4 crystallizes in the hexagonal P6_3/m space group. Si(1) is bonded to one N(1) and three equivalent N(2) atoms to form corner-sharing SiN4 tetrahedra. There are two inequivalent N sites. In the first N site, N(2) is bonded in a trigonal planar geometry to three equivalent Si(1) atoms. In the second N site, N(1) is bonded in a trigonal planar geometry to three equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_Si3N4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.605
_cell_length_b   7.605
_cell_length_c   2.905
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   145.497
_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
  Si  Si0  1  0.231  0.825  0.750  1.0
  Si  Si1  1  0.406  0.231  0.250  1.0
  Si  Si2  1  0.825  0.594  0.250  1.0
  Si  Si3  1  0.175  0.406  0.750  1.0
  Si  Si4  1  0.594  0.769  0.750  1.0
  Si  Si5  1  0.769  0.175  0.250  1.0
  N  N6  1  0.333  0.667  0.750  1.0
  N  N7  1  0.667  0.333  0.250  1.0
  N  N8  1  0.969  0.670  0.750  1.0
  N  N9  1  0.299  0.969  0.250  1.0
  N  N10  1  0.670  0.701  0.250  1.0
  N  N11  1  0.330  0.299  0.750  1.0
  N  N12  1  0.031  0.330  0.250  1.0
  N  N13  1  0.701  0.031  0.750  1.0
[/CIF]
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