The material described by La4Al2O9 crystallizes in the triclinic P1 space group. There are four inequivalent La sites. In the first La site, La(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(5), one O(7), and one O(9) atom. In the second La site, La(2) is bonded in a 5-coordinate geometry to one O(4), one O(6), one O(7), one O(8), and one O(9) atom. In the third La site, La(3) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), one O(8), and one O(9) atom. In the fourth La site, La(4) is bonded to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form distorted LaO6 octahedra that share  a cornercorner with one Al(2)O4 tetrahedra, corners with two equivalent Al(1)O4 tetrahedra, and  an edgeedge with one Al(2)O4 tetrahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form AlO4 tetrahedra that share corners with two equivalent La(4)O6 octahedra and  a cornercorner with one Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-53°. In the second Al site, Al(2) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form AlO4 tetrahedra that share  a cornercorner with one La(4)O6 octahedra,  a cornercorner with one Al(1)O4 tetrahedra, and  an edgeedge with one La(4)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one La(1), one La(3), one Al(1), and one Al(2) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one La(3), one La(4), and one Al(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one La(1), one La(3), and one Al(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one La(2), one La(4), and one Al(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one La(1), one La(3), one La(4), and one Al(1) atom. In the sixth O site, O(6) is bonded to one La(2), one La(3), one La(4), and one Al(2) atom to form distorted edge-sharing OLa3Al trigonal pyramids. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one La(1), one La(2), and one La(4) atom. In the eighth O site, O(8) is bonded to one La(2), one La(3), one La(4), and one Al(2) atom to form distorted edge-sharing OLa3Al tetrahedra. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one La(1), one La(2), and one La(3) atom. is represented by the CIF card [CIF]
data_La4Al2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.589
_cell_length_b   6.420
_cell_length_c   7.479
_cell_angle_alpha   88.656
_cell_angle_beta   94.413
_cell_angle_gamma   91.011
_symmetry_Int_Tables_number   1
_cell_volume   267.439
_cell_formula_units_Z   1
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
  La  La0  1  0.156  0.860  0.707  1.0
  La  La1  1  0.129  0.673  0.227  1.0
  La  La2  1  0.730  0.415  0.872  1.0
  La  La3  1  0.692  0.163  0.367  1.0
  Al  Al4  1  0.225  0.340  0.660  1.0
  Al  Al5  1  0.221  0.212  0.089  1.0
  O  O6  1  0.127  0.204  0.857  1.0
  O  O7  1  0.942  0.391  0.555  1.0
  O  O8  1  0.394  0.572  0.700  1.0
  O  O9  1  0.349  0.978  0.174  1.0
  O  O10  1  0.435  0.151  0.609  1.0
  O  O11  1  0.441  0.410  0.139  1.0
  O  O12  1  0.944  0.876  0.436  1.0
  O  O13  1  0.950  0.314  0.158  1.0
  O  O14  1  0.942  0.706  0.939  1.0
[/CIF]
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The material described by La4Al2O9 crystallizes in the triclinic P1 space group. There are four inequivalent La sites. In the first La site, La(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(5), one O(7), and one O(9) atom. In the second La site, La(2) is bonded in a 5-coordinate geometry to one O(4), one O(6), one O(7), one O(8), and one O(9) atom. In the third La site, La(3) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), one O(8), and one O(9) atom. In the fourth La site, La(4) is bonded to one O(2), one O(4), one O(5), one O(6), one O(7), and one O(8) atom to form distorted LaO6 octahedra that share  a cornercorner with one Al(2)O4 tetrahedra, corners with two equivalent Al(1)O4 tetrahedra, and  an edgeedge with one Al(2)O4 tetrahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form AlO4 tetrahedra that share corners with two equivalent La(4)O6 octahedra and  a cornercorner with one Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-53°. In the second Al site, Al(2) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form AlO4 tetrahedra that share  a cornercorner with one La(4)O6 octahedra,  a cornercorner with one Al(1)O4 tetrahedra, and  an edgeedge with one La(4)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one La(1), one La(3), one Al(1), and one Al(2) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one La(3), one La(4), and one Al(1) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one La(1), one La(3), and one Al(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one La(2), one La(4), and one Al(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one La(1), one La(3), one La(4), and one Al(1) atom. In the sixth O site, O(6) is bonded to one La(2), one La(3), one La(4), and one Al(2) atom to form distorted edge-sharing OLa3Al trigonal pyramids. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one La(1), one La(2), and one La(4) atom. In the eighth O site, O(8) is bonded to one La(2), one La(3), one La(4), and one Al(2) atom to form distorted edge-sharing OLa3Al tetrahedra. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one La(1), one La(2), and one La(3) atom. is represented by the CIF card [CIF]
data_La4Al2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.589
_cell_length_b   6.420
_cell_length_c   7.479
_cell_angle_alpha   88.656
_cell_angle_beta   94.413
_cell_angle_gamma   91.011
_symmetry_Int_Tables_number   1
_cell_volume   267.439
_cell_formula_units_Z   1
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
  La  La0  1  0.156  0.860  0.707  1.0
  La  La1  1  0.129  0.673  0.227  1.0
  La  La2  1  0.730  0.415  0.872  1.0
  La  La3  1  0.692  0.163  0.367  1.0
  Al  Al4  1  0.225  0.340  0.660  1.0
  Al  Al5  1  0.221  0.212  0.089  1.0
  O  O6  1  0.127  0.204  0.857  1.0
  O  O7  1  0.942  0.391  0.555  1.0
  O  O8  1  0.394  0.572  0.700  1.0
  O  O9  1  0.349  0.978  0.174  1.0
  O  O10  1  0.435  0.151  0.609  1.0
  O  O11  1  0.441  0.410  0.139  1.0
  O  O12  1  0.944  0.876  0.436  1.0
  O  O13  1  0.950  0.314  0.158  1.0
  O  O14  1  0.942  0.706  0.939  1.0
[/CIF]
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