The compound described by Ca5(SiN3)2 crystallizes in the monoclinic C2/m space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one N(3), one N(4), two equivalent N(1), and two equivalent N(2) atoms. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one N(3), two equivalent N(1), and two equivalent N(2) atoms. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to two equivalent N(4) and four equivalent N(1) atoms. In the fourth Ca site, Ca(4) is bonded in a 4-coordinate geometry to two equivalent N(3) and four equivalent N(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent N(1) and two equivalent N(4) atoms to form edge-sharing SiN4 tetrahedra. In the second Si site, Si(2) is bonded to two equivalent N(2) and two equivalent N(3) atoms to form edge-sharing SiN4 tetrahedra. There are four inequivalent N sites. In the first N site, N(2) is bonded in a 6-coordinate geometry to one Ca(2), two equivalent Ca(1), two equivalent Ca(4), and one Si(2) atom. In the second N site, N(3) is bonded in a 7-coordinate geometry to one Ca(2), two equivalent Ca(1), two equivalent Ca(4), and two equivalent Si(2) atoms. In the third N site, N(4) is bonded in a 6-coordinate geometry to two equivalent Ca(1), two equivalent Ca(3), and two equivalent Si(1) atoms. In the fourth N site, N(1) is bonded to one Ca(2), two equivalent Ca(1), two equivalent Ca(3), and one Si(1) atom to form a mixture of distorted corner and edge-sharing NCa5Si octahedra. The corner-sharing octahedral tilt angles range from 19-76°. is represented by the CIF file [CIF]
data_Ca5(SiN3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.893
_cell_length_b   5.893
_cell_length_c   12.007
_cell_angle_alpha   85.091
_cell_angle_beta   85.091
_cell_angle_gamma   115.960
_symmetry_Int_Tables_number   1
_cell_volume   369.981
_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
  Ca  Ca0  1  0.730  0.380  0.739  1.0
  Ca  Ca1  1  0.380  0.730  0.739  1.0
  Ca  Ca2  1  0.270  0.620  0.261  1.0
  Ca  Ca3  1  0.620  0.270  0.261  1.0
  Ca  Ca4  1  0.090  0.090  0.793  1.0
  Ca  Ca5  1  0.910  0.910  0.207  1.0
  Ca  Ca6  1  0.813  0.187  0.500  1.0
  Ca  Ca7  1  0.187  0.813  0.500  1.0
  Ca  Ca8  1  0.759  0.241  0.000  1.0
  Ca  Ca9  1  0.241  0.759  0.000  1.0
  Si  Si10  1  0.351  0.351  0.575  1.0
  Si  Si11  1  0.649  0.649  0.425  1.0
  Si  Si12  1  0.675  0.675  0.931  1.0
  Si  Si13  1  0.325  0.325  0.069  1.0
  N  N14  1  0.096  0.389  0.638  1.0
  N  N15  1  0.389  0.096  0.638  1.0
  N  N16  1  0.904  0.611  0.362  1.0
  N  N17  1  0.611  0.904  0.362  1.0
  N  N18  1  0.945  0.657  0.873  1.0
  N  N19  1  0.657  0.945  0.873  1.0
  N  N20  1  0.055  0.343  0.127  1.0
  N  N21  1  0.343  0.055  0.127  1.0
  N  N22  1  0.391  0.391  0.915  1.0
  N  N23  1  0.609  0.609  0.085  1.0
  N  N24  1  0.357  0.357  0.426  1.0
  N  N25  1  0.643  0.643  0.574  1.0
[/CIF]
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The compound described by Ca5(SiN3)2 crystallizes in the monoclinic C2/m space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to one N(3), one N(4), two equivalent N(1), and two equivalent N(2) atoms. In the second Ca site, Ca(2) is bonded in a 5-coordinate geometry to one N(3), two equivalent N(1), and two equivalent N(2) atoms. In the third Ca site, Ca(3) is bonded in a 6-coordinate geometry to two equivalent N(4) and four equivalent N(1) atoms. In the fourth Ca site, Ca(4) is bonded in a 4-coordinate geometry to two equivalent N(3) and four equivalent N(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent N(1) and two equivalent N(4) atoms to form edge-sharing SiN4 tetrahedra. In the second Si site, Si(2) is bonded to two equivalent N(2) and two equivalent N(3) atoms to form edge-sharing SiN4 tetrahedra. There are four inequivalent N sites. In the first N site, N(2) is bonded in a 6-coordinate geometry to one Ca(2), two equivalent Ca(1), two equivalent Ca(4), and one Si(2) atom. In the second N site, N(3) is bonded in a 7-coordinate geometry to one Ca(2), two equivalent Ca(1), two equivalent Ca(4), and two equivalent Si(2) atoms. In the third N site, N(4) is bonded in a 6-coordinate geometry to two equivalent Ca(1), two equivalent Ca(3), and two equivalent Si(1) atoms. In the fourth N site, N(1) is bonded to one Ca(2), two equivalent Ca(1), two equivalent Ca(3), and one Si(1) atom to form a mixture of distorted corner and edge-sharing NCa5Si octahedra. The corner-sharing octahedral tilt angles range from 19-76°. is represented by the CIF file [CIF]
data_Ca5(SiN3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.893
_cell_length_b   5.893
_cell_length_c   12.007
_cell_angle_alpha   85.091
_cell_angle_beta   85.091
_cell_angle_gamma   115.960
_symmetry_Int_Tables_number   1
_cell_volume   369.981
_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
  Ca  Ca0  1  0.730  0.380  0.739  1.0
  Ca  Ca1  1  0.380  0.730  0.739  1.0
  Ca  Ca2  1  0.270  0.620  0.261  1.0
  Ca  Ca3  1  0.620  0.270  0.261  1.0
  Ca  Ca4  1  0.090  0.090  0.793  1.0
  Ca  Ca5  1  0.910  0.910  0.207  1.0
  Ca  Ca6  1  0.813  0.187  0.500  1.0
  Ca  Ca7  1  0.187  0.813  0.500  1.0
  Ca  Ca8  1  0.759  0.241  0.000  1.0
  Ca  Ca9  1  0.241  0.759  0.000  1.0
  Si  Si10  1  0.351  0.351  0.575  1.0
  Si  Si11  1  0.649  0.649  0.425  1.0
  Si  Si12  1  0.675  0.675  0.931  1.0
  Si  Si13  1  0.325  0.325  0.069  1.0
  N  N14  1  0.096  0.389  0.638  1.0
  N  N15  1  0.389  0.096  0.638  1.0
  N  N16  1  0.904  0.611  0.362  1.0
  N  N17  1  0.611  0.904  0.362  1.0
  N  N18  1  0.945  0.657  0.873  1.0
  N  N19  1  0.657  0.945  0.873  1.0
  N  N20  1  0.055  0.343  0.127  1.0
  N  N21  1  0.343  0.055  0.127  1.0
  N  N22  1  0.391  0.391  0.915  1.0
  N  N23  1  0.609  0.609  0.085  1.0
  N  N24  1  0.357  0.357  0.426  1.0
  N  N25  1  0.643  0.643  0.574  1.0
[/CIF]
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