The material structure described by Ca5(SiN3)2 crystallizes in the monoclinic C2/c space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to two equivalent N(1), two equivalent N(2), and two equivalent N(3) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to two equivalent N(1), two equivalent N(2), and two equivalent N(3) atoms. In the third Ca site, Ca(3) is bonded to one N(3), two equivalent N(1), and two equivalent N(2) atoms to form distorted CaN5 trigonal bipyramids that share corners with two equivalent Si(1)N4 tetrahedra, corners with two equivalent Ca(3)N5 trigonal bipyramids, edges with two equivalent Si(1)N4 tetrahedra, and  an edgeedge with one Ca(3)N5 trigonal bipyramid. Si(1) is bonded to one N(1), one N(2), and two equivalent N(3) atoms to form SiN4 tetrahedra that share corners with two equivalent Ca(3)N5 trigonal bipyramids,  an edgeedge with one Si(1)N4 tetrahedra, and edges with two equivalent Ca(3)N5 trigonal bipyramids. There are three inequivalent N sites. In the first 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 18-75°. In the second N site, N(2) 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 face, corner, and edge-sharing NCa5Si octahedra. The corner-sharing octahedral tilt angles range from 18-75°. In the third N site, N(3) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(3), two equivalent Ca(1), and two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_Ca5(SiN3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.760
_cell_length_b   5.760
_cell_length_c   12.726
_cell_angle_alpha   81.278
_cell_angle_beta   81.278
_cell_angle_gamma   63.244
_symmetry_Int_Tables_number   1
_cell_volume   371.003
_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  0.325  0.805  0.001  1.0
  Ca  Ca1  1  0.619  0.381  0.250  1.0
  Ca  Ca2  1  0.068  0.239  0.784  1.0
  Ca  Ca3  1  0.381  0.619  0.750  1.0
  Ca  Ca4  1  0.195  0.675  0.499  1.0
  Ca  Ca5  1  0.805  0.325  0.501  1.0
  Ca  Ca6  1  0.239  0.068  0.284  1.0
  Ca  Ca7  1  0.675  0.195  0.999  1.0
  Ca  Ca8  1  0.932  0.761  0.216  1.0
  Ca  Ca9  1  0.761  0.932  0.716  1.0
  Si  Si10  1  0.093  0.354  0.076  1.0
  Si  Si11  1  0.354  0.093  0.576  1.0
  Si  Si12  1  0.646  0.907  0.424  1.0
  Si  Si13  1  0.907  0.646  0.924  1.0
  N  N14  1  0.609  0.693  0.352  1.0
  N  N15  1  0.102  0.015  0.627  1.0
  N  N16  1  0.655  0.793  0.562  1.0
  N  N17  1  0.015  0.102  0.127  1.0
  N  N18  1  0.391  0.307  0.648  1.0
  N  N19  1  0.345  0.207  0.438  1.0
  N  N20  1  0.985  0.898  0.873  1.0
  N  N21  1  0.693  0.609  0.852  1.0
  N  N22  1  0.207  0.345  0.938  1.0
  N  N23  1  0.898  0.985  0.373  1.0
  N  N24  1  0.793  0.655  0.062  1.0
  N  N25  1  0.307  0.391  0.148  1.0
[/CIF]
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The material structure described by Ca5(SiN3)2 crystallizes in the monoclinic C2/c space group. There are three inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 6-coordinate geometry to two equivalent N(1), two equivalent N(2), and two equivalent N(3) atoms. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to two equivalent N(1), two equivalent N(2), and two equivalent N(3) atoms. In the third Ca site, Ca(3) is bonded to one N(3), two equivalent N(1), and two equivalent N(2) atoms to form distorted CaN5 trigonal bipyramids that share corners with two equivalent Si(1)N4 tetrahedra, corners with two equivalent Ca(3)N5 trigonal bipyramids, edges with two equivalent Si(1)N4 tetrahedra, and  an edgeedge with one Ca(3)N5 trigonal bipyramid. Si(1) is bonded to one N(1), one N(2), and two equivalent N(3) atoms to form SiN4 tetrahedra that share corners with two equivalent Ca(3)N5 trigonal bipyramids,  an edgeedge with one Si(1)N4 tetrahedra, and edges with two equivalent Ca(3)N5 trigonal bipyramids. There are three inequivalent N sites. In the first 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 18-75°. In the second N site, N(2) 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 face, corner, and edge-sharing NCa5Si octahedra. The corner-sharing octahedral tilt angles range from 18-75°. In the third N site, N(3) is bonded in a 6-coordinate geometry to one Ca(2), one Ca(3), two equivalent Ca(1), and two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_Ca5(SiN3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.760
_cell_length_b   5.760
_cell_length_c   12.726
_cell_angle_alpha   81.278
_cell_angle_beta   81.278
_cell_angle_gamma   63.244
_symmetry_Int_Tables_number   1
_cell_volume   371.003
_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  0.325  0.805  0.001  1.0
  Ca  Ca1  1  0.619  0.381  0.250  1.0
  Ca  Ca2  1  0.068  0.239  0.784  1.0
  Ca  Ca3  1  0.381  0.619  0.750  1.0
  Ca  Ca4  1  0.195  0.675  0.499  1.0
  Ca  Ca5  1  0.805  0.325  0.501  1.0
  Ca  Ca6  1  0.239  0.068  0.284  1.0
  Ca  Ca7  1  0.675  0.195  0.999  1.0
  Ca  Ca8  1  0.932  0.761  0.216  1.0
  Ca  Ca9  1  0.761  0.932  0.716  1.0
  Si  Si10  1  0.093  0.354  0.076  1.0
  Si  Si11  1  0.354  0.093  0.576  1.0
  Si  Si12  1  0.646  0.907  0.424  1.0
  Si  Si13  1  0.907  0.646  0.924  1.0
  N  N14  1  0.609  0.693  0.352  1.0
  N  N15  1  0.102  0.015  0.627  1.0
  N  N16  1  0.655  0.793  0.562  1.0
  N  N17  1  0.015  0.102  0.127  1.0
  N  N18  1  0.391  0.307  0.648  1.0
  N  N19  1  0.345  0.207  0.438  1.0
  N  N20  1  0.985  0.898  0.873  1.0
  N  N21  1  0.693  0.609  0.852  1.0
  N  N22  1  0.207  0.345  0.938  1.0
  N  N23  1  0.898  0.985  0.373  1.0
  N  N24  1  0.793  0.655  0.062  1.0
  N  N25  1  0.307  0.391  0.148  1.0
[/CIF]
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