The material structure described by Y2AlN3 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to two equivalent N(1), two equivalent N(3), and three equivalent N(2) atoms. In the second Y site, Y(2) is bonded to two equivalent N(2), two equivalent N(3), and three equivalent N(1) atoms to form distorted YN7 pentagonal bipyramids that share corners with four equivalent Y(2)N7 pentagonal bipyramids,  a cornercorner with one Al(1)N4 tetrahedra, edges with three equivalent Y(2)N7 pentagonal bipyramids, and edges with four equivalent Al(1)N4 tetrahedra. Al(1) is bonded to one N(1), one N(2), and two equivalent N(3) atoms to form AlN4 tetrahedra that share  a cornercorner with one Y(2)N7 pentagonal bipyramid, corners with two equivalent Al(1)N4 tetrahedra, and edges with four equivalent Y(2)N7 pentagonal bipyramids. There are three inequivalent N sites. In the first N site, N(3) is bonded in a 6-coordinate geometry to two equivalent Y(1), two equivalent Y(2), and two equivalent Al(1) atoms. In the second N site, N(1) is bonded in a 6-coordinate geometry to two equivalent Y(1), three equivalent Y(2), and one Al(1) atom. In the third N site, N(2) is bonded to two equivalent Y(2), three equivalent Y(1), and one Al(1) atom to form a mixture of distorted corner and edge-sharing NY5Al octahedra. The corner-sharing octahedral tilt angles are 20°. is represented by the CIF card [CIF]
data_Y2AlN3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.958
_cell_length_b   10.554
_cell_length_c   11.176
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   27.657
_symmetry_Int_Tables_number   1
_cell_volume   326.187
_cell_formula_units_Z   4
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  0.000  0.471  0.651  1.0
  Y  Y1  1  0.000  0.529  0.349  1.0
  Y  Y2  1  0.000  0.029  0.151  1.0
  Y  Y3  1  0.000  0.971  0.849  1.0
  Y  Y4  1  0.000  0.142  0.577  1.0
  Y  Y5  1  0.000  0.858  0.423  1.0
  Y  Y6  1  0.000  0.358  0.077  1.0
  Y  Y7  1  0.000  0.642  0.923  1.0
  Al  Al8  1  0.000  0.249  0.837  1.0
  Al  Al9  1  0.000  0.751  0.163  1.0
  Al  Al10  1  0.000  0.251  0.337  1.0
  Al  Al11  1  0.000  0.749  0.663  1.0
  N  N12  1  0.000  0.152  0.981  1.0
  N  N13  1  0.000  0.848  0.019  1.0
  N  N14  1  0.000  0.348  0.481  1.0
  N  N15  1  0.000  0.652  0.519  1.0
  N  N16  1  0.000  0.427  0.862  1.0
  N  N17  1  0.000  0.573  0.138  1.0
  N  N18  1  0.000  0.073  0.362  1.0
  N  N19  1  0.000  0.927  0.638  1.0
  N  N20  1  0.500  0.429  0.750  1.0
  N  N21  1  0.500  0.071  0.250  1.0
  N  N22  1  0.500  0.571  0.250  1.0
  N  N23  1  0.500  0.929  0.750  1.0
[/CIF]
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The material structure described by Y2AlN3 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 7-coordinate geometry to two equivalent N(1), two equivalent N(3), and three equivalent N(2) atoms. In the second Y site, Y(2) is bonded to two equivalent N(2), two equivalent N(3), and three equivalent N(1) atoms to form distorted YN7 pentagonal bipyramids that share corners with four equivalent Y(2)N7 pentagonal bipyramids,  a cornercorner with one Al(1)N4 tetrahedra, edges with three equivalent Y(2)N7 pentagonal bipyramids, and edges with four equivalent Al(1)N4 tetrahedra. Al(1) is bonded to one N(1), one N(2), and two equivalent N(3) atoms to form AlN4 tetrahedra that share  a cornercorner with one Y(2)N7 pentagonal bipyramid, corners with two equivalent Al(1)N4 tetrahedra, and edges with four equivalent Y(2)N7 pentagonal bipyramids. There are three inequivalent N sites. In the first N site, N(3) is bonded in a 6-coordinate geometry to two equivalent Y(1), two equivalent Y(2), and two equivalent Al(1) atoms. In the second N site, N(1) is bonded in a 6-coordinate geometry to two equivalent Y(1), three equivalent Y(2), and one Al(1) atom. In the third N site, N(2) is bonded to two equivalent Y(2), three equivalent Y(1), and one Al(1) atom to form a mixture of distorted corner and edge-sharing NY5Al octahedra. The corner-sharing octahedral tilt angles are 20°. is represented by the CIF card [CIF]
data_Y2AlN3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.958
_cell_length_b   10.554
_cell_length_c   11.176
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   27.657
_symmetry_Int_Tables_number   1
_cell_volume   326.187
_cell_formula_units_Z   4
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  0.000  0.471  0.651  1.0
  Y  Y1  1  0.000  0.529  0.349  1.0
  Y  Y2  1  0.000  0.029  0.151  1.0
  Y  Y3  1  0.000  0.971  0.849  1.0
  Y  Y4  1  0.000  0.142  0.577  1.0
  Y  Y5  1  0.000  0.858  0.423  1.0
  Y  Y6  1  0.000  0.358  0.077  1.0
  Y  Y7  1  0.000  0.642  0.923  1.0
  Al  Al8  1  0.000  0.249  0.837  1.0
  Al  Al9  1  0.000  0.751  0.163  1.0
  Al  Al10  1  0.000  0.251  0.337  1.0
  Al  Al11  1  0.000  0.749  0.663  1.0
  N  N12  1  0.000  0.152  0.981  1.0
  N  N13  1  0.000  0.848  0.019  1.0
  N  N14  1  0.000  0.348  0.481  1.0
  N  N15  1  0.000  0.652  0.519  1.0
  N  N16  1  0.000  0.427  0.862  1.0
  N  N17  1  0.000  0.573  0.138  1.0
  N  N18  1  0.000  0.073  0.362  1.0
  N  N19  1  0.000  0.927  0.638  1.0
  N  N20  1  0.500  0.429  0.750  1.0
  N  N21  1  0.500  0.071  0.250  1.0
  N  N22  1  0.500  0.571  0.250  1.0
  N  N23  1  0.500  0.929  0.750  1.0
[/CIF]
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