The material described by (W)2Ca2W7Al4Si8O24 crystallizes in the monoclinic C2/m space group. The structure consists of four 7440-33-7 atoms inside a Ca2W7Al4Si8O24 framework. In the Ca2W7Al4Si8O24 framework, Ca(1) is bonded in a 4-coordinate geometry to one W(1), two equivalent O(1), and two equivalent O(4) atoms. There are three inequivalent W sites. In the first W site, W(4) is bonded in a single-bond geometry to one W(2) and one O(5) atom. In the second W site, W(1) is bonded in a distorted single-bond geometry to one Ca(1) and one W(2) atom. In the third W site, W(2) is bonded in a 6-coordinate geometry to two equivalent W(1) and four equivalent W(4) atoms. Al(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form AlO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and one O(6) 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. In the second Si site, Si(2) is bonded to one O(1), one O(5), one O(6), 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 seven inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(7) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Al(1), and one Si(2) atom. In the fourth O site, O(5) is bonded in a 3-coordinate geometry to one W(4), one Al(1), and one Si(2) atom. In the fifth O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the sixth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Al(1) and one Si(1) atom. In the seventh O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one Al(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Ca2Al4Si8(W3O8)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.897
_cell_length_b   10.263
_cell_length_c   10.263
_cell_angle_alpha   83.972
_cell_angle_beta   73.823
_cell_angle_gamma   73.823
_symmetry_Int_Tables_number   1
_cell_volume   766.815
_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
  Ca  Ca0  1  0.714  0.751  0.751  1.0
  Ca  Ca1  1  0.286  0.249  0.249  1.0
  Al  Al2  1  0.238  0.173  0.570  1.0
  Al  Al3  1  0.762  0.827  0.430  1.0
  Al  Al4  1  0.762  0.430  0.827  1.0
  Al  Al5  1  0.238  0.570  0.173  1.0
  Si  Si6  1  0.160  0.688  0.463  1.0
  Si  Si7  1  0.840  0.312  0.537  1.0
  Si  Si8  1  0.840  0.537  0.312  1.0
  Si  Si9  1  0.160  0.463  0.688  1.0
  Si  Si10  1  0.347  0.845  0.614  1.0
  Si  Si11  1  0.653  0.155  0.386  1.0
  Si  Si12  1  0.653  0.386  0.155  1.0
  Si  Si13  1  0.347  0.614  0.845  1.0
  W  W14  1  0.296  0.047  0.047  1.0
  W  W15  1  0.704  0.953  0.953  1.0
  W  W16  1  0.000  0.000  0.000  1.0
  W  W17  1  0.500  0.164  0.836  1.0
  W  W18  1  0.500  0.836  0.164  1.0
  W  W19  1  0.082  0.989  0.285  1.0
  W  W20  1  0.918  0.011  0.715  1.0
  W  W21  1  0.918  0.715  0.011  1.0
  W  W22  1  0.082  0.285  0.989  1.0
  O  O23  1  0.436  0.163  0.433  1.0
  O  O24  1  0.564  0.837  0.567  1.0
  O  O25  1  0.564  0.567  0.837  1.0
  O  O26  1  0.436  0.433  0.163  1.0
  O  O27  1  0.204  0.537  0.537  1.0
  O  O28  1  0.796  0.463  0.463  1.0
  O  O29  1  0.228  0.299  0.677  1.0
  O  O30  1  0.772  0.701  0.323  1.0
  O  O31  1  0.772  0.323  0.701  1.0
  O  O32  1  0.228  0.677  0.299  1.0
  O  O33  1  0.061  0.240  0.485  1.0
  O  O34  1  0.939  0.760  0.515  1.0
  O  O35  1  0.939  0.515  0.760  1.0
  O  O36  1  0.061  0.485  0.240  1.0
  O  O37  1  0.225  0.005  0.633  1.0
  O  O38  1  0.775  0.995  0.367  1.0
  O  O39  1  0.775  0.367  0.995  1.0
  O  O40  1  0.225  0.633  0.005  1.0
  O  O41  1  0.279  0.777  0.507  1.0
  O  O42  1  0.721  0.223  0.493  1.0
  O  O43  1  0.721  0.493  0.223  1.0
  O  O44  1  0.279  0.507  0.777  1.0
  O  O45  1  0.318  0.760  0.760  1.0
  O  O46  1  0.682  0.240  0.240  1.0
[/CIF]
.
The material described by (W)2Ca2W7Al4Si8O24 crystallizes in the monoclinic C2/m space group. The structure consists of four 7440-33-7 atoms inside a Ca2W7Al4Si8O24 framework. In the Ca2W7Al4Si8O24 framework, Ca(1) is bonded in a 4-coordinate geometry to one W(1), two equivalent O(1), and two equivalent O(4) atoms. There are three inequivalent W sites. In the first W site, W(4) is bonded in a single-bond geometry to one W(2) and one O(5) atom. In the second W site, W(1) is bonded in a distorted single-bond geometry to one Ca(1) and one W(2) atom. In the third W site, W(2) is bonded in a 6-coordinate geometry to two equivalent W(1) and four equivalent W(4) atoms. Al(1) is bonded to one O(1), one O(3), one O(4), and one O(5) atom to form AlO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(3), one O(4), and one O(6) 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. In the second Si site, Si(2) is bonded to one O(1), one O(5), one O(6), 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 seven inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the second O site, O(7) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. In the third O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Al(1), and one Si(2) atom. In the fourth O site, O(5) is bonded in a 3-coordinate geometry to one W(4), one Al(1), and one Si(2) atom. In the fifth O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the sixth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Al(1) and one Si(1) atom. In the seventh O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one Al(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_Ca2Al4Si8(W3O8)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.897
_cell_length_b   10.263
_cell_length_c   10.263
_cell_angle_alpha   83.972
_cell_angle_beta   73.823
_cell_angle_gamma   73.823
_symmetry_Int_Tables_number   1
_cell_volume   766.815
_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
  Ca  Ca0  1  0.714  0.751  0.751  1.0
  Ca  Ca1  1  0.286  0.249  0.249  1.0
  Al  Al2  1  0.238  0.173  0.570  1.0
  Al  Al3  1  0.762  0.827  0.430  1.0
  Al  Al4  1  0.762  0.430  0.827  1.0
  Al  Al5  1  0.238  0.570  0.173  1.0
  Si  Si6  1  0.160  0.688  0.463  1.0
  Si  Si7  1  0.840  0.312  0.537  1.0
  Si  Si8  1  0.840  0.537  0.312  1.0
  Si  Si9  1  0.160  0.463  0.688  1.0
  Si  Si10  1  0.347  0.845  0.614  1.0
  Si  Si11  1  0.653  0.155  0.386  1.0
  Si  Si12  1  0.653  0.386  0.155  1.0
  Si  Si13  1  0.347  0.614  0.845  1.0
  W  W14  1  0.296  0.047  0.047  1.0
  W  W15  1  0.704  0.953  0.953  1.0
  W  W16  1  0.000  0.000  0.000  1.0
  W  W17  1  0.500  0.164  0.836  1.0
  W  W18  1  0.500  0.836  0.164  1.0
  W  W19  1  0.082  0.989  0.285  1.0
  W  W20  1  0.918  0.011  0.715  1.0
  W  W21  1  0.918  0.715  0.011  1.0
  W  W22  1  0.082  0.285  0.989  1.0
  O  O23  1  0.436  0.163  0.433  1.0
  O  O24  1  0.564  0.837  0.567  1.0
  O  O25  1  0.564  0.567  0.837  1.0
  O  O26  1  0.436  0.433  0.163  1.0
  O  O27  1  0.204  0.537  0.537  1.0
  O  O28  1  0.796  0.463  0.463  1.0
  O  O29  1  0.228  0.299  0.677  1.0
  O  O30  1  0.772  0.701  0.323  1.0
  O  O31  1  0.772  0.323  0.701  1.0
  O  O32  1  0.228  0.677  0.299  1.0
  O  O33  1  0.061  0.240  0.485  1.0
  O  O34  1  0.939  0.760  0.515  1.0
  O  O35  1  0.939  0.515  0.760  1.0
  O  O36  1  0.061  0.485  0.240  1.0
  O  O37  1  0.225  0.005  0.633  1.0
  O  O38  1  0.775  0.995  0.367  1.0
  O  O39  1  0.775  0.367  0.995  1.0
  O  O40  1  0.225  0.633  0.005  1.0
  O  O41  1  0.279  0.777  0.507  1.0
  O  O42  1  0.721  0.223  0.493  1.0
  O  O43  1  0.721  0.493  0.223  1.0
  O  O44  1  0.279  0.507  0.777  1.0
  O  O45  1  0.318  0.760  0.760  1.0
  O  O46  1  0.682  0.240  0.240  1.0
[/CIF]
.