The compound described by Al3(SiO5)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form AlO6 octahedra that share corners with five equivalent Si(1)O4 tetrahedra,  an edgeedge with one Al(2)O6 octahedra, and edges with two equivalent Al(1)O6 octahedra. In the second Al site, Al(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with four 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), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with two equivalent Al(2)O6 octahedra and corners with five equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-56°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Al(1) and one Si(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Al(1) and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Al(2) and one Si(1) atom. In the fifth O site, O(5) is bonded in a water-like geometry to one Al(1) and one Al(2) atom. is represented by the CIF card [CIF]
data_Al3(SiO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.606
_cell_length_b   4.883
_cell_length_c   7.527
_cell_angle_alpha   102.593
_cell_angle_beta   104.085
_cell_angle_gamma   100.105
_symmetry_Int_Tables_number   1
_cell_volume   155.517
_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
  Al  Al0  1  0.597  0.796  0.105  1.0
  Al  Al1  1  0.403  0.204  0.895  1.0
  Al  Al2  1  0.000  0.000  0.500  1.0
  Si  Si3  1  0.063  0.403  0.215  1.0
  Si  Si4  1  0.937  0.597  0.785  1.0
  O  O5  1  0.769  0.144  0.060  1.0
  O  O6  1  0.340  0.451  0.112  1.0
  O  O7  1  0.961  0.713  0.263  1.0
  O  O8  1  0.163  0.295  0.407  1.0
  O  O9  1  0.385  0.981  0.651  1.0
  O  O10  1  0.231  0.856  0.940  1.0
  O  O11  1  0.660  0.549  0.888  1.0
  O  O12  1  0.039  0.287  0.737  1.0
  O  O13  1  0.837  0.705  0.593  1.0
  O  O14  1  0.615  0.019  0.349  1.0
[/CIF]
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The compound described by Al3(SiO5)2 crystallizes in the triclinic P-1 space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form AlO6 octahedra that share corners with five equivalent Si(1)O4 tetrahedra,  an edgeedge with one Al(2)O6 octahedra, and edges with two equivalent Al(1)O6 octahedra. In the second Al site, Al(2) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form AlO6 octahedra that share corners with four 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), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with two equivalent Al(2)O6 octahedra and corners with five equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-56°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Al(1) and one Si(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Al(1) and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(2), and one Si(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Al(2) and one Si(1) atom. In the fifth O site, O(5) is bonded in a water-like geometry to one Al(1) and one Al(2) atom. is represented by the CIF card [CIF]
data_Al3(SiO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.606
_cell_length_b   4.883
_cell_length_c   7.527
_cell_angle_alpha   102.593
_cell_angle_beta   104.085
_cell_angle_gamma   100.105
_symmetry_Int_Tables_number   1
_cell_volume   155.517
_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
  Al  Al0  1  0.597  0.796  0.105  1.0
  Al  Al1  1  0.403  0.204  0.895  1.0
  Al  Al2  1  0.000  0.000  0.500  1.0
  Si  Si3  1  0.063  0.403  0.215  1.0
  Si  Si4  1  0.937  0.597  0.785  1.0
  O  O5  1  0.769  0.144  0.060  1.0
  O  O6  1  0.340  0.451  0.112  1.0
  O  O7  1  0.961  0.713  0.263  1.0
  O  O8  1  0.163  0.295  0.407  1.0
  O  O9  1  0.385  0.981  0.651  1.0
  O  O10  1  0.231  0.856  0.940  1.0
  O  O11  1  0.660  0.549  0.888  1.0
  O  O12  1  0.039  0.287  0.737  1.0
  O  O13  1  0.837  0.705  0.593  1.0
  O  O14  1  0.615  0.019  0.349  1.0
[/CIF]
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