The material described by Al3Si3(PbO8)2 crystallizes in the orthorhombic Ccc2 space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(3) and two equivalent O(6) atoms to form AlO4 tetrahedra that share corners with four equivalent Si(2)O4 tetrahedra. In the second Al site, Al(2) is bonded to one O(4), one O(5), one O(7), and one O(8) atom to form AlO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. Pb(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent O(5) and two equivalent O(8) atoms to form SiO4 tetrahedra that share corners with four equivalent Al(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra and corners with two equivalent Al(2)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Pb(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to two equivalent Pb(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Al(1), one Pb(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Al(2), one Pb(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Al(2), one Pb(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Al(2) and one Si(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Al(2) and one Si(1) atom. is represented by the CIF file [CIF]
data_Al3Si3(PbO8)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.166
_cell_length_b   9.166
_cell_length_c   9.120
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.931
_symmetry_Int_Tables_number   1
_cell_volume   766.110
_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
  Al  Al0  1  0.000  0.000  0.259  1.0
  Al  Al1  1  0.514  0.251  0.000  1.0
  Al  Al2  1  0.251  0.514  0.500  1.0
  Al  Al3  1  0.486  0.749  0.000  1.0
  Al  Al4  1  0.749  0.486  0.500  1.0
  Al  Al5  1  0.000  0.000  0.759  1.0
  Si  Si6  1  0.500  0.500  0.252  1.0
  Si  Si7  1  0.997  0.250  0.507  1.0
  Si  Si8  1  0.250  0.997  0.007  1.0
  Si  Si9  1  0.003  0.750  0.507  1.0
  Si  Si10  1  0.750  0.003  0.007  1.0
  Si  Si11  1  0.500  0.500  0.752  1.0
  Pb  Pb12  1  0.330  0.174  0.320  1.0
  Pb  Pb13  1  0.670  0.826  0.320  1.0
  Pb  Pb14  1  0.174  0.330  0.820  1.0
  Pb  Pb15  1  0.826  0.670  0.820  1.0
  O  O16  1  0.104  0.398  0.051  1.0
  O  O17  1  0.896  0.602  0.051  1.0
  O  O18  1  0.083  0.584  0.910  1.0
  O  O19  1  0.917  0.416  0.910  1.0
  O  O20  1  0.584  0.083  0.410  1.0
  O  O21  1  0.398  0.104  0.551  1.0
  O  O22  1  0.602  0.896  0.551  1.0
  O  O23  1  0.416  0.917  0.410  1.0
  O  O24  1  0.059  0.147  0.373  1.0
  O  O25  1  0.360  0.139  0.054  1.0
  O  O26  1  0.361  0.448  0.357  1.0
  O  O27  1  0.941  0.853  0.373  1.0
  O  O28  1  0.640  0.861  0.054  1.0
  O  O29  1  0.639  0.552  0.357  1.0
  O  O30  1  0.031  0.843  0.657  1.0
  O  O31  1  0.343  0.861  0.955  1.0
  O  O32  1  0.355  0.539  0.659  1.0
  O  O33  1  0.969  0.157  0.657  1.0
  O  O34  1  0.657  0.139  0.955  1.0
  O  O35  1  0.645  0.461  0.659  1.0
  O  O36  1  0.539  0.355  0.159  1.0
  O  O37  1  0.843  0.031  0.157  1.0
  O  O38  1  0.861  0.343  0.455  1.0
  O  O39  1  0.448  0.361  0.857  1.0
  O  O40  1  0.147  0.059  0.873  1.0
  O  O41  1  0.139  0.360  0.554  1.0
  O  O42  1  0.552  0.639  0.857  1.0
  O  O43  1  0.853  0.941  0.873  1.0
  O  O44  1  0.861  0.640  0.554  1.0
  O  O45  1  0.461  0.645  0.159  1.0
  O  O46  1  0.157  0.969  0.157  1.0
  O  O47  1  0.139  0.657  0.455  1.0
[/CIF]
.
The material described by Al3Si3(PbO8)2 crystallizes in the orthorhombic Ccc2 space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to two equivalent O(3) and two equivalent O(6) atoms to form AlO4 tetrahedra that share corners with four equivalent Si(2)O4 tetrahedra. In the second Al site, Al(2) is bonded to one O(4), one O(5), one O(7), and one O(8) atom to form AlO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. Pb(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent O(5) and two equivalent O(8) atoms to form SiO4 tetrahedra that share corners with four equivalent Al(2)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra and corners with two equivalent Al(2)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Pb(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to two equivalent Pb(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Al(1), one Pb(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Al(2), one Pb(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Al(2), one Pb(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Al(2) and one Si(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Al(2) and one Si(1) atom. is represented by the CIF file [CIF]
data_Al3Si3(PbO8)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.166
_cell_length_b   9.166
_cell_length_c   9.120
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.931
_symmetry_Int_Tables_number   1
_cell_volume   766.110
_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
  Al  Al0  1  0.000  0.000  0.259  1.0
  Al  Al1  1  0.514  0.251  0.000  1.0
  Al  Al2  1  0.251  0.514  0.500  1.0
  Al  Al3  1  0.486  0.749  0.000  1.0
  Al  Al4  1  0.749  0.486  0.500  1.0
  Al  Al5  1  0.000  0.000  0.759  1.0
  Si  Si6  1  0.500  0.500  0.252  1.0
  Si  Si7  1  0.997  0.250  0.507  1.0
  Si  Si8  1  0.250  0.997  0.007  1.0
  Si  Si9  1  0.003  0.750  0.507  1.0
  Si  Si10  1  0.750  0.003  0.007  1.0
  Si  Si11  1  0.500  0.500  0.752  1.0
  Pb  Pb12  1  0.330  0.174  0.320  1.0
  Pb  Pb13  1  0.670  0.826  0.320  1.0
  Pb  Pb14  1  0.174  0.330  0.820  1.0
  Pb  Pb15  1  0.826  0.670  0.820  1.0
  O  O16  1  0.104  0.398  0.051  1.0
  O  O17  1  0.896  0.602  0.051  1.0
  O  O18  1  0.083  0.584  0.910  1.0
  O  O19  1  0.917  0.416  0.910  1.0
  O  O20  1  0.584  0.083  0.410  1.0
  O  O21  1  0.398  0.104  0.551  1.0
  O  O22  1  0.602  0.896  0.551  1.0
  O  O23  1  0.416  0.917  0.410  1.0
  O  O24  1  0.059  0.147  0.373  1.0
  O  O25  1  0.360  0.139  0.054  1.0
  O  O26  1  0.361  0.448  0.357  1.0
  O  O27  1  0.941  0.853  0.373  1.0
  O  O28  1  0.640  0.861  0.054  1.0
  O  O29  1  0.639  0.552  0.357  1.0
  O  O30  1  0.031  0.843  0.657  1.0
  O  O31  1  0.343  0.861  0.955  1.0
  O  O32  1  0.355  0.539  0.659  1.0
  O  O33  1  0.969  0.157  0.657  1.0
  O  O34  1  0.657  0.139  0.955  1.0
  O  O35  1  0.645  0.461  0.659  1.0
  O  O36  1  0.539  0.355  0.159  1.0
  O  O37  1  0.843  0.031  0.157  1.0
  O  O38  1  0.861  0.343  0.455  1.0
  O  O39  1  0.448  0.361  0.857  1.0
  O  O40  1  0.147  0.059  0.873  1.0
  O  O41  1  0.139  0.360  0.554  1.0
  O  O42  1  0.552  0.639  0.857  1.0
  O  O43  1  0.853  0.941  0.873  1.0
  O  O44  1  0.861  0.640  0.554  1.0
  O  O45  1  0.461  0.645  0.159  1.0
  O  O46  1  0.157  0.969  0.157  1.0
  O  O47  1  0.139  0.657  0.455  1.0
[/CIF]
.