The compound described by LiAlAs2O7 crystallizes in the monoclinic C2 space group. Li(1) is bonded in a distorted see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. Al(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form AlO6 octahedra that share corners with six equivalent As(1)O4 tetrahedra. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and  a cornercorner with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 24-55°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(1), one Al(1), and one As(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Al(1), and one As(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Al(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to two equivalent As(1) atoms. is represented by the CIF file [CIF]
data_LiAlAs2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.268
_cell_length_b   5.268
_cell_length_c   4.707
_cell_angle_alpha   81.082
_cell_angle_beta   81.082
_cell_angle_gamma   101.244
_symmetry_Int_Tables_number   1
_cell_volume   124.257
_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
  Li  Li0  1  0.246  0.754  0.000  1.0
  Al  Al1  1  0.622  0.378  0.000  1.0
  As  As2  1  0.748  0.821  0.406  1.0
  As  As3  1  0.179  0.252  0.594  1.0
  O  O4  1  0.851  0.638  0.159  1.0
  O  O5  1  0.340  0.452  0.268  1.0
  O  O6  1  0.928  0.376  0.739  1.0
  O  O7  1  0.058  0.942  0.500  1.0
  O  O8  1  0.548  0.660  0.732  1.0
  O  O9  1  0.624  0.072  0.261  1.0
  O  O10  1  0.362  0.149  0.841  1.0
[/CIF]
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The compound described by LiAlAs2O7 crystallizes in the monoclinic C2 space group. Li(1) is bonded in a distorted see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. Al(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form AlO6 octahedra that share corners with six equivalent As(1)O4 tetrahedra. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and  a cornercorner with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 24-55°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Li(1), one Al(1), and one As(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(1), one Al(1), and one As(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Al(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to two equivalent As(1) atoms. is represented by the CIF file [CIF]
data_LiAlAs2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.268
_cell_length_b   5.268
_cell_length_c   4.707
_cell_angle_alpha   81.082
_cell_angle_beta   81.082
_cell_angle_gamma   101.244
_symmetry_Int_Tables_number   1
_cell_volume   124.257
_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
  Li  Li0  1  0.246  0.754  0.000  1.0
  Al  Al1  1  0.622  0.378  0.000  1.0
  As  As2  1  0.748  0.821  0.406  1.0
  As  As3  1  0.179  0.252  0.594  1.0
  O  O4  1  0.851  0.638  0.159  1.0
  O  O5  1  0.340  0.452  0.268  1.0
  O  O6  1  0.928  0.376  0.739  1.0
  O  O7  1  0.058  0.942  0.500  1.0
  O  O8  1  0.548  0.660  0.732  1.0
  O  O9  1  0.624  0.072  0.261  1.0
  O  O10  1  0.362  0.149  0.841  1.0
[/CIF]
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