The structure described by LiAlSi2O6 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Li(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Al(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form AlO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Al(1)O6 octahedra. Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form SiO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-60°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), two equivalent Al(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLiAl2Si tetrahedra. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Li(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(1) and two equivalent Si(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_LiAl(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.410
_cell_length_b   6.410
_cell_length_c   5.275
_cell_angle_alpha   74.676
_cell_angle_beta   74.676
_cell_angle_gamma   82.737
_symmetry_Int_Tables_number   1
_cell_volume   201.227
_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
  Li  Li0  1  0.271  0.730  0.750  1.0
  Li  Li1  1  0.730  0.271  0.250  1.0
  Al  Al2  1  0.905  0.095  0.750  1.0
  Al  Al3  1  0.095  0.905  0.250  1.0
  Si  Si4  1  0.800  0.613  0.758  1.0
  Si  Si5  1  0.387  0.200  0.742  1.0
  Si  Si6  1  0.200  0.387  0.242  1.0
  Si  Si7  1  0.613  0.800  0.258  1.0
  O  O8  1  0.974  0.808  0.641  1.0
  O  O9  1  0.192  0.026  0.859  1.0
  O  O10  1  0.026  0.192  0.359  1.0
  O  O11  1  0.808  0.974  0.141  1.0
  O  O12  1  0.900  0.368  0.800  1.0
  O  O13  1  0.632  0.100  0.700  1.0
  O  O14  1  0.100  0.632  0.200  1.0
  O  O15  1  0.368  0.900  0.300  1.0
  O  O16  1  0.627  0.663  0.565  1.0
  O  O17  1  0.337  0.373  0.935  1.0
  O  O18  1  0.373  0.337  0.435  1.0
  O  O19  1  0.663  0.627  0.065  1.0
[/CIF]
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The structure described by LiAlSi2O6 is Esseneite structured and crystallizes in the monoclinic C2/c space group. Li(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Al(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form AlO6 octahedra that share corners with six equivalent Si(1)O4 tetrahedra and edges with two equivalent Al(1)O6 octahedra. Si(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form SiO4 tetrahedra that share corners with three equivalent Al(1)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-60°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), two equivalent Al(1), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OLiAl2Si tetrahedra. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Li(1), one Al(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Li(1) and two equivalent Si(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_LiAl(SiO3)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.410
_cell_length_b   6.410
_cell_length_c   5.275
_cell_angle_alpha   74.676
_cell_angle_beta   74.676
_cell_angle_gamma   82.737
_symmetry_Int_Tables_number   1
_cell_volume   201.227
_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
  Li  Li0  1  0.271  0.730  0.750  1.0
  Li  Li1  1  0.730  0.271  0.250  1.0
  Al  Al2  1  0.905  0.095  0.750  1.0
  Al  Al3  1  0.095  0.905  0.250  1.0
  Si  Si4  1  0.800  0.613  0.758  1.0
  Si  Si5  1  0.387  0.200  0.742  1.0
  Si  Si6  1  0.200  0.387  0.242  1.0
  Si  Si7  1  0.613  0.800  0.258  1.0
  O  O8  1  0.974  0.808  0.641  1.0
  O  O9  1  0.192  0.026  0.859  1.0
  O  O10  1  0.026  0.192  0.359  1.0
  O  O11  1  0.808  0.974  0.141  1.0
  O  O12  1  0.900  0.368  0.800  1.0
  O  O13  1  0.632  0.100  0.700  1.0
  O  O14  1  0.100  0.632  0.200  1.0
  O  O15  1  0.368  0.900  0.300  1.0
  O  O16  1  0.627  0.663  0.565  1.0
  O  O17  1  0.337  0.373  0.935  1.0
  O  O18  1  0.373  0.337  0.435  1.0
  O  O19  1  0.663  0.627  0.065  1.0
[/CIF]
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