The material structure described by KAlSi3O8 crystallizes in the triclinic P-1 space group. K(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(7), one O(8), and two equivalent O(1) atoms. Al(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(2), one O(3), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Al(1)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Al(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(1), one Si(2), and one Si(3) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one K(1), one Al(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one K(1), one Si(1), and one Si(3) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one K(1), one Al(1), and one Si(3) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one K(1), one Al(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one K(1), one Si(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_KAlSi3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.326
_cell_length_b   7.723
_cell_length_c   8.027
_cell_angle_alpha   112.912
_cell_angle_beta   104.452
_cell_angle_gamma   103.494
_symmetry_Int_Tables_number   1
_cell_volume   376.251
_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
  K  K0  1  0.863  0.709  0.724  1.0
  K  K1  1  0.137  0.291  0.276  1.0
  Al  Al2  1  0.783  0.178  0.800  1.0
  Al  Al3  1  0.217  0.822  0.200  1.0
  Si  Si4  1  0.768  0.807  0.171  1.0
  Si  Si5  1  0.232  0.193  0.829  1.0
  Si  Si6  1  0.660  0.407  0.166  1.0
  Si  Si7  1  0.340  0.593  0.834  1.0
  Si  Si8  1  0.648  0.177  0.405  1.0
  Si  Si9  1  0.352  0.823  0.595  1.0
  O  O10  1  0.018  0.146  0.855  1.0
  O  O11  1  0.982  0.854  0.145  1.0
  O  O12  1  0.713  0.366  0.355  1.0
  O  O13  1  0.287  0.634  0.645  1.0
  O  O14  1  0.780  0.326  0.029  1.0
  O  O15  1  0.220  0.674  0.971  1.0
  O  O16  1  0.759  0.023  0.309  1.0
  O  O17  1  0.241  0.977  0.691  1.0
  O  O18  1  0.748  0.283  0.642  1.0
  O  O19  1  0.252  0.717  0.358  1.0
  O  O20  1  0.731  0.655  0.267  1.0
  O  O21  1  0.269  0.345  0.733  1.0
  O  O22  1  0.596  0.934  0.688  1.0
  O  O23  1  0.404  0.066  0.312  1.0
  O  O24  1  0.588  0.697  0.951  1.0
  O  O25  1  0.412  0.303  0.049  1.0
[/CIF]
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The material structure described by KAlSi3O8 crystallizes in the triclinic P-1 space group. K(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(7), one O(8), and two equivalent O(1) atoms. Al(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(3)O4 tetrahedra. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(2), one O(3), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(2), one O(4), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Al(1)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Al(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(1), one Si(2), and one Si(3) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one K(1), one Al(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one K(1), one Si(1), and one Si(3) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one K(1), one Al(1), and one Si(3) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one K(1), one Al(1), and one Si(3) atom. In the eighth O site, O(8) is bonded in a distorted bent 150 degrees geometry to one K(1), one Si(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_KAlSi3O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.326
_cell_length_b   7.723
_cell_length_c   8.027
_cell_angle_alpha   112.912
_cell_angle_beta   104.452
_cell_angle_gamma   103.494
_symmetry_Int_Tables_number   1
_cell_volume   376.251
_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
  K  K0  1  0.863  0.709  0.724  1.0
  K  K1  1  0.137  0.291  0.276  1.0
  Al  Al2  1  0.783  0.178  0.800  1.0
  Al  Al3  1  0.217  0.822  0.200  1.0
  Si  Si4  1  0.768  0.807  0.171  1.0
  Si  Si5  1  0.232  0.193  0.829  1.0
  Si  Si6  1  0.660  0.407  0.166  1.0
  Si  Si7  1  0.340  0.593  0.834  1.0
  Si  Si8  1  0.648  0.177  0.405  1.0
  Si  Si9  1  0.352  0.823  0.595  1.0
  O  O10  1  0.018  0.146  0.855  1.0
  O  O11  1  0.982  0.854  0.145  1.0
  O  O12  1  0.713  0.366  0.355  1.0
  O  O13  1  0.287  0.634  0.645  1.0
  O  O14  1  0.780  0.326  0.029  1.0
  O  O15  1  0.220  0.674  0.971  1.0
  O  O16  1  0.759  0.023  0.309  1.0
  O  O17  1  0.241  0.977  0.691  1.0
  O  O18  1  0.748  0.283  0.642  1.0
  O  O19  1  0.252  0.717  0.358  1.0
  O  O20  1  0.731  0.655  0.267  1.0
  O  O21  1  0.269  0.345  0.733  1.0
  O  O22  1  0.596  0.934  0.688  1.0
  O  O23  1  0.404  0.066  0.312  1.0
  O  O24  1  0.588  0.697  0.951  1.0
  O  O25  1  0.412  0.303  0.049  1.0
[/CIF]
.