The compound described by Y2SiAlO5N crystallizes in the triclinic P1 space group. There are six inequivalent Y sites. In the first Y site, Y(1) is bonded to one O(11), one O(15), two equivalent O(3), and two equivalent O(7) atoms to form distorted YO6 pentagonal pyramids that share corners with four equivalent Y(1)O6 pentagonal pyramids, corners with two equivalent Si(3)O4 tetrahedra,  an edgeedge with one Y(6)N2O4 pentagonal pyramid, and  an edgeedge with one Si(3)O4 tetrahedra. In the second Y site, Y(2) is bonded in a 6-coordinate geometry to one N(3), one O(13), two equivalent O(4), and two equivalent O(9) atoms. In the third Y site, Y(3) is bonded to one O(12), one O(14), two equivalent O(10), and two equivalent O(2) atoms to form distorted YO6 pentagonal pyramids that share corners with four equivalent Y(3)O6 pentagonal pyramids, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Y(5)O6 pentagonal pyramid, and  an edgeedge with one Si(2)O4 tetrahedra. In the fourth Y site, Y(4) is bonded in a 6-coordinate geometry to one N(3), two equivalent N(2), one O(13), and two equivalent O(6) atoms. In the fifth Y site, Y(5) is bonded to one O(12), one O(14), two equivalent O(1), and two equivalent O(8) atoms to form distorted YO6 pentagonal pyramids that share corners with four equivalent Y(5)O6 pentagonal pyramids, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Y(3)O6 pentagonal pyramid, and  an edgeedge with one Si(2)O4 tetrahedra. In the sixth Y site, Y(6) is bonded to two equivalent N(1), one O(11), one O(15), and two equivalent O(5) atoms to form distorted YN2O4 pentagonal pyramids that share corners with four equivalent Y(6)N2O4 pentagonal pyramids, corners with two equivalent Si(3)O4 tetrahedra,  an edgeedge with one Y(1)O6 pentagonal pyramid, and  an edgeedge with one Si(3)O4 tetrahedra. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a bent 150 degrees geometry to one O(7) and one O(8) atom. In the second Al site, Al(2) is bonded in a bent 150 degrees geometry to one N(1) and one O(9) atom. In the third Al site, Al(3) is bonded in a distorted bent 120 degrees geometry to two equivalent N(2) and one O(10) atom. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted tetrahedral geometry to one N(3), one O(13), one O(4), and one O(6) atom. In the second Si site, Si(2) is bonded to one O(1), one O(12), one O(14), and one O(2) atom to form SiO4 tetrahedra that share corners with two equivalent Y(3)O6 pentagonal pyramids, corners with two equivalent Y(5)O6 pentagonal pyramids,  an edgeedge with one Y(3)O6 pentagonal pyramid, and  an edgeedge with one Y(5)O6 pentagonal pyramid. In the third Si site, Si(3) is bonded to one O(11), one O(15), one O(3), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Y(6)N2O4 pentagonal pyramids, corners with two equivalent Y(1)O6 pentagonal pyramids,  an edgeedge with one Y(6)N2O4 pentagonal pyramid, and  an edgeedge with one Y(1)O6 pentagonal pyramid. There are three inequivalent N sites. In the first N site, N(1) is bonded in a trigonal non-coplanar geometry to two equivalent Y(6) and one Al(2) atom. In the second N site, N(2) is bonded in a 4-coordinate geometry to two equivalent Y(4) and two equivalent Al(3) atoms. In the third N site, N(3) is bonded in a trigonal planar geometry to one Y(2), one Y(4), and one Si(1) atom. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Y(5) and one Si(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Y(3) and one Si(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Y(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Y(2) and one Si(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Y(6) and one Si(3) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Y(4) and one Si(1) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to two equivalent Y(1) and one Al(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to two equivalent Y(5) and one Al(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to two equivalent Y(2) and one Al(2) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to two equivalent Y(3) and one Al(3) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Y(1), one Y(6), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Y(3), one Y(5), and one Si(2) atom. In the thirteenth O site, O(13) is bonded in a 1-coordinate geometry to one Y(2), one Y(4), and one Si(1) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one Y(3), one Y(5), and one Si(2) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal non-coplanar geometry to one Y(1), one Y(6), and one Si(3) atom. is represented by the CIF file [CIF]
data_Y2AlSiNO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.049
_cell_length_b   5.180
_cell_length_c   27.452
_cell_angle_alpha   89.098
_cell_angle_beta   86.050
_cell_angle_gamma   124.306
_symmetry_Int_Tables_number   1
_cell_volume   473.530
_cell_formula_units_Z   3
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
  Y  Y0  1  0.061  0.109  0.353  1.0
  Y  Y1  1  0.094  0.990  0.681  1.0
  Y  Y2  1  0.119  0.140  0.012  1.0
  Y  Y3  1  0.987  0.938  0.821  1.0
  Y  Y4  1  0.028  0.078  0.146  1.0
  Y  Y5  1  0.974  0.059  0.487  1.0
  Al  Al6  1  0.683  0.321  0.246  1.0
  Al  Al7  1  0.693  0.386  0.576  1.0
  Al  Al8  1  0.747  0.303  0.908  1.0
  Si  Si9  1  0.232  0.611  0.751  1.0
  Si  Si10  1  0.262  0.634  0.081  1.0
  Si  Si11  1  0.211  0.613  0.419  1.0
  N  N12  1  0.462  0.088  0.536  1.0
  N  N13  1  0.368  0.314  0.877  1.0
  N  N14  1  0.136  0.247  0.751  1.0
  O  O15  1  0.423  0.629  0.135  1.0
  O  O16  1  0.510  0.667  0.028  1.0
  O  O17  1  0.455  0.648  0.365  1.0
  O  O18  1  0.477  0.838  0.699  1.0
  O  O19  1  0.379  0.601  0.472  1.0
  O  O20  1  0.390  0.794  0.803  1.0
  O  O21  1  0.630  0.203  0.306  1.0
  O  O22  1  0.546  0.149  0.193  1.0
  O  O23  1  0.646  0.447  0.636  1.0
  O  O24  1  0.701  0.220  0.970  1.0
  O  O25  1  0.090  0.861  0.418  1.0
  O  O26  1  0.138  0.882  0.080  1.0
  O  O27  1  0.828  0.620  0.750  1.0
  O  O28  1  0.894  0.262  0.082  1.0
  O  O29  1  0.842  0.241  0.418  1.0
[/CIF]
.
The compound described by Y2SiAlO5N crystallizes in the triclinic P1 space group. There are six inequivalent Y sites. In the first Y site, Y(1) is bonded to one O(11), one O(15), two equivalent O(3), and two equivalent O(7) atoms to form distorted YO6 pentagonal pyramids that share corners with four equivalent Y(1)O6 pentagonal pyramids, corners with two equivalent Si(3)O4 tetrahedra,  an edgeedge with one Y(6)N2O4 pentagonal pyramid, and  an edgeedge with one Si(3)O4 tetrahedra. In the second Y site, Y(2) is bonded in a 6-coordinate geometry to one N(3), one O(13), two equivalent O(4), and two equivalent O(9) atoms. In the third Y site, Y(3) is bonded to one O(12), one O(14), two equivalent O(10), and two equivalent O(2) atoms to form distorted YO6 pentagonal pyramids that share corners with four equivalent Y(3)O6 pentagonal pyramids, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Y(5)O6 pentagonal pyramid, and  an edgeedge with one Si(2)O4 tetrahedra. In the fourth Y site, Y(4) is bonded in a 6-coordinate geometry to one N(3), two equivalent N(2), one O(13), and two equivalent O(6) atoms. In the fifth Y site, Y(5) is bonded to one O(12), one O(14), two equivalent O(1), and two equivalent O(8) atoms to form distorted YO6 pentagonal pyramids that share corners with four equivalent Y(5)O6 pentagonal pyramids, corners with two equivalent Si(2)O4 tetrahedra,  an edgeedge with one Y(3)O6 pentagonal pyramid, and  an edgeedge with one Si(2)O4 tetrahedra. In the sixth Y site, Y(6) is bonded to two equivalent N(1), one O(11), one O(15), and two equivalent O(5) atoms to form distorted YN2O4 pentagonal pyramids that share corners with four equivalent Y(6)N2O4 pentagonal pyramids, corners with two equivalent Si(3)O4 tetrahedra,  an edgeedge with one Y(1)O6 pentagonal pyramid, and  an edgeedge with one Si(3)O4 tetrahedra. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a bent 150 degrees geometry to one O(7) and one O(8) atom. In the second Al site, Al(2) is bonded in a bent 150 degrees geometry to one N(1) and one O(9) atom. In the third Al site, Al(3) is bonded in a distorted bent 120 degrees geometry to two equivalent N(2) and one O(10) atom. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a distorted tetrahedral geometry to one N(3), one O(13), one O(4), and one O(6) atom. In the second Si site, Si(2) is bonded to one O(1), one O(12), one O(14), and one O(2) atom to form SiO4 tetrahedra that share corners with two equivalent Y(3)O6 pentagonal pyramids, corners with two equivalent Y(5)O6 pentagonal pyramids,  an edgeedge with one Y(3)O6 pentagonal pyramid, and  an edgeedge with one Y(5)O6 pentagonal pyramid. In the third Si site, Si(3) is bonded to one O(11), one O(15), one O(3), and one O(5) atom to form SiO4 tetrahedra that share corners with two equivalent Y(6)N2O4 pentagonal pyramids, corners with two equivalent Y(1)O6 pentagonal pyramids,  an edgeedge with one Y(6)N2O4 pentagonal pyramid, and  an edgeedge with one Y(1)O6 pentagonal pyramid. There are three inequivalent N sites. In the first N site, N(1) is bonded in a trigonal non-coplanar geometry to two equivalent Y(6) and one Al(2) atom. In the second N site, N(2) is bonded in a 4-coordinate geometry to two equivalent Y(4) and two equivalent Al(3) atoms. In the third N site, N(3) is bonded in a trigonal planar geometry to one Y(2), one Y(4), and one Si(1) atom. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to two equivalent Y(5) and one Si(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Y(3) and one Si(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Y(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Y(2) and one Si(1) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Y(6) and one Si(3) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to two equivalent Y(4) and one Si(1) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to two equivalent Y(1) and one Al(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to two equivalent Y(5) and one Al(1) atom. In the ninth O site, O(9) is bonded in a distorted trigonal planar geometry to two equivalent Y(2) and one Al(2) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to two equivalent Y(3) and one Al(3) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Y(1), one Y(6), and one Si(3) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Y(3), one Y(5), and one Si(2) atom. In the thirteenth O site, O(13) is bonded in a 1-coordinate geometry to one Y(2), one Y(4), and one Si(1) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one Y(3), one Y(5), and one Si(2) atom. In the fifteenth O site, O(15) is bonded in a distorted trigonal non-coplanar geometry to one Y(1), one Y(6), and one Si(3) atom. is represented by the CIF file [CIF]
data_Y2AlSiNO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.049
_cell_length_b   5.180
_cell_length_c   27.452
_cell_angle_alpha   89.098
_cell_angle_beta   86.050
_cell_angle_gamma   124.306
_symmetry_Int_Tables_number   1
_cell_volume   473.530
_cell_formula_units_Z   3
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
  Y  Y0  1  0.061  0.109  0.353  1.0
  Y  Y1  1  0.094  0.990  0.681  1.0
  Y  Y2  1  0.119  0.140  0.012  1.0
  Y  Y3  1  0.987  0.938  0.821  1.0
  Y  Y4  1  0.028  0.078  0.146  1.0
  Y  Y5  1  0.974  0.059  0.487  1.0
  Al  Al6  1  0.683  0.321  0.246  1.0
  Al  Al7  1  0.693  0.386  0.576  1.0
  Al  Al8  1  0.747  0.303  0.908  1.0
  Si  Si9  1  0.232  0.611  0.751  1.0
  Si  Si10  1  0.262  0.634  0.081  1.0
  Si  Si11  1  0.211  0.613  0.419  1.0
  N  N12  1  0.462  0.088  0.536  1.0
  N  N13  1  0.368  0.314  0.877  1.0
  N  N14  1  0.136  0.247  0.751  1.0
  O  O15  1  0.423  0.629  0.135  1.0
  O  O16  1  0.510  0.667  0.028  1.0
  O  O17  1  0.455  0.648  0.365  1.0
  O  O18  1  0.477  0.838  0.699  1.0
  O  O19  1  0.379  0.601  0.472  1.0
  O  O20  1  0.390  0.794  0.803  1.0
  O  O21  1  0.630  0.203  0.306  1.0
  O  O22  1  0.546  0.149  0.193  1.0
  O  O23  1  0.646  0.447  0.636  1.0
  O  O24  1  0.701  0.220  0.970  1.0
  O  O25  1  0.090  0.861  0.418  1.0
  O  O26  1  0.138  0.882  0.080  1.0
  O  O27  1  0.828  0.620  0.750  1.0
  O  O28  1  0.894  0.262  0.082  1.0
  O  O29  1  0.842  0.241  0.418  1.0
[/CIF]
.