The material described by SrAlSi5O2N7 crystallizes in the monoclinic Pc space group. Sr(1) is bonded in a 2-coordinate geometry to one N(1), one N(7), and one O(2) atom. Al(1) is bonded in a 4-coordinate geometry to one N(1), one N(3), one N(6), and one O(1) atom. There are five inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted T-shaped geometry to one N(3), one N(4), and one O(1) atom. In the second Si site, Si(2) is bonded in a distorted trigonal pyramidal geometry to one N(1), one N(6), one O(1), and one O(2) atom. In the third Si site, Si(3) is bonded in a distorted T-shaped geometry to one N(2), one N(7), and one O(2) atom. In the fourth Si site, Si(4) is bonded in a distorted trigonal non-coplanar geometry to one N(2), one N(4), and one N(7) atom. In the fifth Si site, Si(5) is bonded in a distorted trigonal non-coplanar geometry to one N(3), one N(4), and one N(5) atom. There are seven inequivalent N sites. In the first N site, N(1) is bonded in a 4-coordinate geometry to one Sr(1), one Al(1), one Si(2), and one N(2) atom. In the second N site, N(2) is bonded in a 3-coordinate geometry to one Si(3), one Si(4), and one N(1) atom. In the third N site, N(3) is bonded in a distorted trigonal planar geometry to one Al(1), one Si(1), and one Si(5) atom. In the fourth N site, N(4) is bonded in a 3-coordinate geometry to one Si(1), one Si(4), and one Si(5) atom. In the fifth N site, N(5) is bonded in a distorted trigonal planar geometry to one Si(5), one N(6), and one N(7) atom. In the sixth N site, N(6) is bonded in a 2-coordinate geometry to one Al(1), one Si(2), and one N(5) atom. In the seventh N site, N(7) is bonded in a 4-coordinate geometry to one Sr(1), one Si(3), one Si(4), and one N(5) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Al(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Sr(1), one Si(2), and one Si(3) atom. is represented by the CIF file [CIF]
data_SrAlSi5N7O2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.110
_cell_length_b   6.603
_cell_length_c   9.700
_cell_angle_alpha   56.905
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   381.464
_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
  Sr  Sr0  1  0.305  0.103  0.048  1.0
  Sr  Sr1  1  0.695  0.103  0.548  1.0
  Al  Al2  1  0.509  0.542  0.687  1.0
  Al  Al3  1  0.491  0.542  0.187  1.0
  Si  Si4  1  0.854  0.668  0.534  1.0
  Si  Si5  1  0.456  0.966  0.370  1.0
  Si  Si6  1  0.146  0.668  0.034  1.0
  Si  Si7  1  0.544  0.966  0.870  1.0
  Si  Si8  1  0.941  0.028  0.925  1.0
  Si  Si9  1  0.808  0.540  0.274  1.0
  Si  Si10  1  0.144  0.365  0.446  1.0
  Si  Si11  1  0.059  0.028  0.425  1.0
  Si  Si12  1  0.192  0.540  0.774  1.0
  Si  Si13  1  0.856  0.365  0.946  1.0
  N  N14  1  0.400  0.884  0.569  1.0
  N  N15  1  0.600  0.884  0.069  1.0
  N  N16  1  0.802  0.832  0.107  1.0
  N  N17  1  0.240  0.561  0.237  1.0
  N  N18  1  0.073  0.496  0.951  1.0
  N  N19  1  0.198  0.832  0.607  1.0
  N  N20  1  0.760  0.561  0.737  1.0
  N  N21  1  0.750  0.291  0.142  1.0
  N  N22  1  0.551  0.235  0.201  1.0
  N  N23  1  0.927  0.496  0.451  1.0
  N  N24  1  0.250  0.291  0.642  1.0
  N  N25  1  0.449  0.235  0.701  1.0
  N  N26  1  0.113  0.286  0.759  1.0
  N  N27  1  0.887  0.286  0.259  1.0
  O  O28  1  0.623  0.740  0.444  1.0
  O  O29  1  0.377  0.740  0.944  1.0
  O  O30  1  0.771  0.997  0.806  1.0
  O  O31  1  0.229  0.997  0.306  1.0
[/CIF]
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The material described by SrAlSi5O2N7 crystallizes in the monoclinic Pc space group. Sr(1) is bonded in a 2-coordinate geometry to one N(1), one N(7), and one O(2) atom. Al(1) is bonded in a 4-coordinate geometry to one N(1), one N(3), one N(6), and one O(1) atom. There are five inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted T-shaped geometry to one N(3), one N(4), and one O(1) atom. In the second Si site, Si(2) is bonded in a distorted trigonal pyramidal geometry to one N(1), one N(6), one O(1), and one O(2) atom. In the third Si site, Si(3) is bonded in a distorted T-shaped geometry to one N(2), one N(7), and one O(2) atom. In the fourth Si site, Si(4) is bonded in a distorted trigonal non-coplanar geometry to one N(2), one N(4), and one N(7) atom. In the fifth Si site, Si(5) is bonded in a distorted trigonal non-coplanar geometry to one N(3), one N(4), and one N(5) atom. There are seven inequivalent N sites. In the first N site, N(1) is bonded in a 4-coordinate geometry to one Sr(1), one Al(1), one Si(2), and one N(2) atom. In the second N site, N(2) is bonded in a 3-coordinate geometry to one Si(3), one Si(4), and one N(1) atom. In the third N site, N(3) is bonded in a distorted trigonal planar geometry to one Al(1), one Si(1), and one Si(5) atom. In the fourth N site, N(4) is bonded in a 3-coordinate geometry to one Si(1), one Si(4), and one Si(5) atom. In the fifth N site, N(5) is bonded in a distorted trigonal planar geometry to one Si(5), one N(6), and one N(7) atom. In the sixth N site, N(6) is bonded in a 2-coordinate geometry to one Al(1), one Si(2), and one N(5) atom. In the seventh N site, N(7) is bonded in a 4-coordinate geometry to one Sr(1), one Si(3), one Si(4), and one N(5) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Al(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Sr(1), one Si(2), and one Si(3) atom. is represented by the CIF file [CIF]
data_SrAlSi5N7O2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.110
_cell_length_b   6.603
_cell_length_c   9.700
_cell_angle_alpha   56.905
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   381.464
_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
  Sr  Sr0  1  0.305  0.103  0.048  1.0
  Sr  Sr1  1  0.695  0.103  0.548  1.0
  Al  Al2  1  0.509  0.542  0.687  1.0
  Al  Al3  1  0.491  0.542  0.187  1.0
  Si  Si4  1  0.854  0.668  0.534  1.0
  Si  Si5  1  0.456  0.966  0.370  1.0
  Si  Si6  1  0.146  0.668  0.034  1.0
  Si  Si7  1  0.544  0.966  0.870  1.0
  Si  Si8  1  0.941  0.028  0.925  1.0
  Si  Si9  1  0.808  0.540  0.274  1.0
  Si  Si10  1  0.144  0.365  0.446  1.0
  Si  Si11  1  0.059  0.028  0.425  1.0
  Si  Si12  1  0.192  0.540  0.774  1.0
  Si  Si13  1  0.856  0.365  0.946  1.0
  N  N14  1  0.400  0.884  0.569  1.0
  N  N15  1  0.600  0.884  0.069  1.0
  N  N16  1  0.802  0.832  0.107  1.0
  N  N17  1  0.240  0.561  0.237  1.0
  N  N18  1  0.073  0.496  0.951  1.0
  N  N19  1  0.198  0.832  0.607  1.0
  N  N20  1  0.760  0.561  0.737  1.0
  N  N21  1  0.750  0.291  0.142  1.0
  N  N22  1  0.551  0.235  0.201  1.0
  N  N23  1  0.927  0.496  0.451  1.0
  N  N24  1  0.250  0.291  0.642  1.0
  N  N25  1  0.449  0.235  0.701  1.0
  N  N26  1  0.113  0.286  0.759  1.0
  N  N27  1  0.887  0.286  0.259  1.0
  O  O28  1  0.623  0.740  0.444  1.0
  O  O29  1  0.377  0.740  0.944  1.0
  O  O30  1  0.771  0.997  0.806  1.0
  O  O31  1  0.229  0.997  0.306  1.0
[/CIF]
.