The structure described by Al2SiO5 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form AlO6 octahedra that share corners with four equivalent Al(2)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and edges with two equivalent Al(1)O6 octahedra. In the second Al site, Al(2) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form AlO4 tetrahedra that share corners with four equivalent Al(1)O6 octahedra and corners with three equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-63°. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with four equivalent Al(1)O6 octahedra and corners with three equivalent Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-55°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Al(1), one Al(2), and one Si(1) atom. In the second O site, O(2) is bonded in a linear geometry to one Al(2) and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Al(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Al(2) and two equivalent Al(1) atoms. is represented by the CIF file [CIF]
data_Al2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.767
_cell_length_b   7.492
_cell_length_c   7.663
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   331.094
_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
  Al  Al0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.500  0.000  0.000  1.0
  Al  Al2  1  0.000  0.500  0.500  1.0
  Al  Al3  1  0.500  0.500  0.500  1.0
  Al  Al4  1  0.250  0.358  0.844  1.0
  Al  Al5  1  0.750  0.642  0.156  1.0
  Al  Al6  1  0.750  0.858  0.656  1.0
  Al  Al7  1  0.250  0.142  0.344  1.0
  Si  Si8  1  0.750  0.154  0.340  1.0
  Si  Si9  1  0.250  0.846  0.660  1.0
  Si  Si10  1  0.250  0.654  0.160  1.0
  Si  Si11  1  0.750  0.346  0.840  1.0
  O  O12  1  0.014  0.626  0.278  1.0
  O  O13  1  0.514  0.374  0.722  1.0
  O  O14  1  0.986  0.126  0.222  1.0
  O  O15  1  0.486  0.874  0.778  1.0
  O  O16  1  0.986  0.374  0.722  1.0
  O  O17  1  0.486  0.626  0.278  1.0
  O  O18  1  0.014  0.874  0.778  1.0
  O  O19  1  0.514  0.126  0.222  1.0
  O  O20  1  0.750  0.023  0.502  1.0
  O  O21  1  0.250  0.977  0.498  1.0
  O  O22  1  0.250  0.523  0.998  1.0
  O  O23  1  0.750  0.477  0.002  1.0
  O  O24  1  0.750  0.360  0.409  1.0
  O  O25  1  0.250  0.640  0.591  1.0
  O  O26  1  0.250  0.860  0.091  1.0
  O  O27  1  0.750  0.140  0.909  1.0
  O  O28  1  0.250  0.357  0.433  1.0
  O  O29  1  0.750  0.643  0.567  1.0
  O  O30  1  0.750  0.857  0.067  1.0
  O  O31  1  0.250  0.143  0.933  1.0
[/CIF]
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The structure described by Al2SiO5 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form AlO6 octahedra that share corners with four equivalent Al(2)O4 tetrahedra, corners with four equivalent Si(1)O4 tetrahedra, and edges with two equivalent Al(1)O6 octahedra. In the second Al site, Al(2) is bonded to one O(2), one O(4), and two equivalent O(1) atoms to form AlO4 tetrahedra that share corners with four equivalent Al(1)O6 octahedra and corners with three equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-63°. Si(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SiO4 tetrahedra that share corners with four equivalent Al(1)O6 octahedra and corners with three equivalent Al(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-55°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Al(1), one Al(2), and one Si(1) atom. In the second O site, O(2) is bonded in a linear geometry to one Al(2) and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Al(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Al(2) and two equivalent Al(1) atoms. is represented by the CIF file [CIF]
data_Al2SiO5
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.767
_cell_length_b   7.492
_cell_length_c   7.663
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   331.094
_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
  Al  Al0  1  0.000  0.000  0.000  1.0
  Al  Al1  1  0.500  0.000  0.000  1.0
  Al  Al2  1  0.000  0.500  0.500  1.0
  Al  Al3  1  0.500  0.500  0.500  1.0
  Al  Al4  1  0.250  0.358  0.844  1.0
  Al  Al5  1  0.750  0.642  0.156  1.0
  Al  Al6  1  0.750  0.858  0.656  1.0
  Al  Al7  1  0.250  0.142  0.344  1.0
  Si  Si8  1  0.750  0.154  0.340  1.0
  Si  Si9  1  0.250  0.846  0.660  1.0
  Si  Si10  1  0.250  0.654  0.160  1.0
  Si  Si11  1  0.750  0.346  0.840  1.0
  O  O12  1  0.014  0.626  0.278  1.0
  O  O13  1  0.514  0.374  0.722  1.0
  O  O14  1  0.986  0.126  0.222  1.0
  O  O15  1  0.486  0.874  0.778  1.0
  O  O16  1  0.986  0.374  0.722  1.0
  O  O17  1  0.486  0.626  0.278  1.0
  O  O18  1  0.014  0.874  0.778  1.0
  O  O19  1  0.514  0.126  0.222  1.0
  O  O20  1  0.750  0.023  0.502  1.0
  O  O21  1  0.250  0.977  0.498  1.0
  O  O22  1  0.250  0.523  0.998  1.0
  O  O23  1  0.750  0.477  0.002  1.0
  O  O24  1  0.750  0.360  0.409  1.0
  O  O25  1  0.250  0.640  0.591  1.0
  O  O26  1  0.250  0.860  0.091  1.0
  O  O27  1  0.750  0.140  0.909  1.0
  O  O28  1  0.250  0.357  0.433  1.0
  O  O29  1  0.750  0.643  0.567  1.0
  O  O30  1  0.750  0.857  0.067  1.0
  O  O31  1  0.250  0.143  0.933  1.0
[/CIF]
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