The crystal structure described by K2Al2Si3O10 crystallizes in the orthorhombic Fdd2 space group. K(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(5), and two equivalent O(2) atoms. Al(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with three equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent O(1) and two equivalent O(5) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(1)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(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with three equivalent Al(1)O4 tetrahedra. There are five inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 120 degrees geometry to one K(1), one Al(1), and one Si(2) atom. In the second O site, O(4) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(2) atom. In the third O site, O(5) is bonded in a distorted bent 150 degrees geometry to one K(1), one Si(1), and one Si(2) atom. In the fourth O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Al(1), and one Si(1) atom. In the fifth O site, O(2) is bonded in a distorted bent 120 degrees geometry to two equivalent K(1), one Al(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_K2Al2Si3O10
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.681
_cell_length_b   9.854
_cell_length_c   9.266
_cell_angle_alpha   83.037
_cell_angle_beta   50.473
_cell_angle_gamma   46.490
_symmetry_Int_Tables_number   1
_cell_volume   533.720
_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  0.968  0.158  0.615  1.0
  K  K1  1  0.260  0.615  0.158  1.0
  K  K2  1  0.635  0.990  0.282  1.0
  K  K3  1  0.092  0.282  0.990  1.0
  Al  Al4  1  0.574  0.731  0.997  1.0
  Al  Al5  1  0.699  0.997  0.731  1.0
  Al  Al6  1  0.253  0.551  0.676  1.0
  Al  Al7  1  0.519  0.676  0.551  1.0
  Si  Si8  1  0.255  0.245  0.245  1.0
  Si  Si9  1  0.005  0.995  0.995  1.0
  Si  Si10  1  0.552  0.505  0.237  1.0
  Si  Si11  1  0.707  0.237  0.505  1.0
  Si  Si12  1  0.013  0.543  0.698  1.0
  Si  Si13  1  0.745  0.698  0.543  1.0
  O  O14  1  0.344  0.018  0.213  1.0
  O  O15  1  0.425  0.213  0.018  1.0
  O  O16  1  0.037  0.825  0.906  1.0
  O  O17  1  0.232  0.906  0.825  1.0
  O  O18  1  0.508  0.609  0.102  1.0
  O  O19  1  0.781  0.102  0.609  1.0
  O  O20  1  0.148  0.469  0.742  1.0
  O  O21  1  0.641  0.742  0.469  1.0
  O  O22  1  0.836  0.559  0.876  1.0
  O  O23  1  0.729  0.876  0.559  1.0
  O  O24  1  0.374  0.521  0.414  1.0
  O  O25  1  0.691  0.414  0.521  1.0
  O  O26  1  0.530  0.640  0.360  1.0
  O  O27  1  0.470  0.360  0.640  1.0
  O  O28  1  0.890  0.780  0.720  1.0
  O  O29  1  0.610  0.720  0.780  1.0
  O  O30  1  0.817  0.234  0.036  1.0
  O  O31  1  0.913  0.036  0.234  1.0
  O  O32  1  0.214  0.337  0.433  1.0
  O  O33  1  0.016  0.433  0.337  1.0
[/CIF]
.
The crystal structure described by K2Al2Si3O10 crystallizes in the orthorhombic Fdd2 space group. K(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(5), and two equivalent O(2) atoms. Al(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with three equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent O(1) and two equivalent O(5) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(1)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(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with three equivalent Al(1)O4 tetrahedra. There are five inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 120 degrees geometry to one K(1), one Al(1), and one Si(2) atom. In the second O site, O(4) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(2) atom. In the third O site, O(5) is bonded in a distorted bent 150 degrees geometry to one K(1), one Si(1), and one Si(2) atom. In the fourth O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Al(1), and one Si(1) atom. In the fifth O site, O(2) is bonded in a distorted bent 120 degrees geometry to two equivalent K(1), one Al(1), and one Si(2) atom. is represented by the CIF file [CIF]
data_K2Al2Si3O10
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.681
_cell_length_b   9.854
_cell_length_c   9.266
_cell_angle_alpha   83.037
_cell_angle_beta   50.473
_cell_angle_gamma   46.490
_symmetry_Int_Tables_number   1
_cell_volume   533.720
_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  0.968  0.158  0.615  1.0
  K  K1  1  0.260  0.615  0.158  1.0
  K  K2  1  0.635  0.990  0.282  1.0
  K  K3  1  0.092  0.282  0.990  1.0
  Al  Al4  1  0.574  0.731  0.997  1.0
  Al  Al5  1  0.699  0.997  0.731  1.0
  Al  Al6  1  0.253  0.551  0.676  1.0
  Al  Al7  1  0.519  0.676  0.551  1.0
  Si  Si8  1  0.255  0.245  0.245  1.0
  Si  Si9  1  0.005  0.995  0.995  1.0
  Si  Si10  1  0.552  0.505  0.237  1.0
  Si  Si11  1  0.707  0.237  0.505  1.0
  Si  Si12  1  0.013  0.543  0.698  1.0
  Si  Si13  1  0.745  0.698  0.543  1.0
  O  O14  1  0.344  0.018  0.213  1.0
  O  O15  1  0.425  0.213  0.018  1.0
  O  O16  1  0.037  0.825  0.906  1.0
  O  O17  1  0.232  0.906  0.825  1.0
  O  O18  1  0.508  0.609  0.102  1.0
  O  O19  1  0.781  0.102  0.609  1.0
  O  O20  1  0.148  0.469  0.742  1.0
  O  O21  1  0.641  0.742  0.469  1.0
  O  O22  1  0.836  0.559  0.876  1.0
  O  O23  1  0.729  0.876  0.559  1.0
  O  O24  1  0.374  0.521  0.414  1.0
  O  O25  1  0.691  0.414  0.521  1.0
  O  O26  1  0.530  0.640  0.360  1.0
  O  O27  1  0.470  0.360  0.640  1.0
  O  O28  1  0.890  0.780  0.720  1.0
  O  O29  1  0.610  0.720  0.780  1.0
  O  O30  1  0.817  0.234  0.036  1.0
  O  O31  1  0.913  0.036  0.234  1.0
  O  O32  1  0.214  0.337  0.433  1.0
  O  O33  1  0.016  0.433  0.337  1.0
[/CIF]
.