The material structure described by SrAl2Si2O8 crystallizes in the monoclinic C2/c space group. Sr(1) is bonded in a 6-coordinate geometry to one O(1), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2), one O(6), one O(7), and one O(8) atom to form AlO4 tetrahedra that share corners with three equivalent Si(1)O4 tetrahedra. In the second Al site, Al(2) is bonded in a trigonal planar geometry to one O(1), one O(3), and one O(5) atom. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(5), one O(7), and one O(8) atom to form SiO4 tetrahedra that share corners with three equivalent Al(1)O4 tetrahedra. In the second Si site, Si(2) is bonded in a trigonal non-coplanar geometry to one O(1), one O(3), and one O(4) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Sr(1), one Al(2), and one Si(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Al(1) and one Si(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Al(2) and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Sr(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Sr(1), one Al(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Sr(1) and one Al(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Sr(1), one Al(1), and one Si(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Sr(1), one Al(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_SrAl2(SiO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.498
_cell_length_b   9.498
_cell_length_c   10.545
_cell_angle_alpha   78.596
_cell_angle_beta   78.596
_cell_angle_gamma   80.301
_symmetry_Int_Tables_number   1
_cell_volume   905.768
_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
  Sr  Sr0  1  0.319  0.054  0.276  1.0
  Sr  Sr1  1  0.681  0.946  0.724  1.0
  Sr  Sr2  1  0.946  0.681  0.224  1.0
  Sr  Sr3  1  0.054  0.319  0.776  1.0
  Al  Al4  1  0.058  0.111  0.110  1.0
  Al  Al5  1  0.443  0.712  0.925  1.0
  Al  Al6  1  0.889  0.942  0.390  1.0
  Al  Al7  1  0.712  0.443  0.425  1.0
  Al  Al8  1  0.111  0.058  0.610  1.0
  Al  Al9  1  0.557  0.288  0.075  1.0
  Al  Al10  1  0.942  0.889  0.890  1.0
  Al  Al11  1  0.288  0.557  0.575  1.0
  Si  Si12  1  0.989  0.230  0.375  1.0
  Si  Si13  1  0.011  0.770  0.625  1.0
  Si  Si14  1  0.253  0.457  0.079  1.0
  Si  Si15  1  0.747  0.543  0.921  1.0
  Si  Si16  1  0.770  0.011  0.125  1.0
  Si  Si17  1  0.230  0.989  0.875  1.0
  Si  Si18  1  0.543  0.747  0.421  1.0
  Si  Si19  1  0.457  0.253  0.579  1.0
  O  O20  1  0.628  0.690  0.875  1.0
  O  O21  1  0.884  0.130  0.078  1.0
  O  O22  1  0.568  0.351  0.466  1.0
  O  O23  1  0.310  0.372  0.625  1.0
  O  O24  1  0.468  0.837  0.303  1.0
  O  O25  1  0.896  0.391  0.387  1.0
  O  O26  1  0.649  0.432  0.034  1.0
  O  O27  1  0.069  0.867  0.318  1.0
  O  O28  1  0.130  0.884  0.578  1.0
  O  O29  1  0.123  0.185  0.462  1.0
  O  O30  1  0.432  0.649  0.534  1.0
  O  O31  1  0.218  0.072  0.724  1.0
  O  O32  1  0.690  0.628  0.375  1.0
  O  O33  1  0.815  0.877  0.038  1.0
  O  O34  1  0.609  0.104  0.113  1.0
  O  O35  1  0.072  0.218  0.224  1.0
  O  O36  1  0.532  0.163  0.697  1.0
  O  O37  1  0.351  0.568  0.966  1.0
  O  O38  1  0.391  0.896  0.887  1.0
  O  O39  1  0.372  0.310  0.125  1.0
  O  O40  1  0.877  0.815  0.538  1.0
  O  O41  1  0.870  0.116  0.422  1.0
  O  O42  1  0.928  0.782  0.776  1.0
  O  O43  1  0.782  0.928  0.276  1.0
  O  O44  1  0.163  0.532  0.197  1.0
  O  O45  1  0.116  0.870  0.922  1.0
  O  O46  1  0.104  0.609  0.613  1.0
  O  O47  1  0.867  0.069  0.818  1.0
  O  O48  1  0.931  0.133  0.682  1.0
  O  O49  1  0.837  0.468  0.803  1.0
  O  O50  1  0.185  0.123  0.962  1.0
  O  O51  1  0.133  0.931  0.182  1.0
[/CIF]
.
The material structure described by SrAl2Si2O8 crystallizes in the monoclinic C2/c space group. Sr(1) is bonded in a 6-coordinate geometry to one O(1), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2), one O(6), one O(7), and one O(8) atom to form AlO4 tetrahedra that share corners with three equivalent Si(1)O4 tetrahedra. In the second Al site, Al(2) is bonded in a trigonal planar geometry to one O(1), one O(3), and one O(5) atom. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(5), one O(7), and one O(8) atom to form SiO4 tetrahedra that share corners with three equivalent Al(1)O4 tetrahedra. In the second Si site, Si(2) is bonded in a trigonal non-coplanar geometry to one O(1), one O(3), and one O(4) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Sr(1), one Al(2), and one Si(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Al(1) and one Si(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Al(2) and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Sr(1) and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Sr(1), one Al(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Sr(1) and one Al(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Sr(1), one Al(1), and one Si(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Sr(1), one Al(1), and one Si(1) atom. is represented by the CIF file [CIF]
data_SrAl2(SiO4)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.498
_cell_length_b   9.498
_cell_length_c   10.545
_cell_angle_alpha   78.596
_cell_angle_beta   78.596
_cell_angle_gamma   80.301
_symmetry_Int_Tables_number   1
_cell_volume   905.768
_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
  Sr  Sr0  1  0.319  0.054  0.276  1.0
  Sr  Sr1  1  0.681  0.946  0.724  1.0
  Sr  Sr2  1  0.946  0.681  0.224  1.0
  Sr  Sr3  1  0.054  0.319  0.776  1.0
  Al  Al4  1  0.058  0.111  0.110  1.0
  Al  Al5  1  0.443  0.712  0.925  1.0
  Al  Al6  1  0.889  0.942  0.390  1.0
  Al  Al7  1  0.712  0.443  0.425  1.0
  Al  Al8  1  0.111  0.058  0.610  1.0
  Al  Al9  1  0.557  0.288  0.075  1.0
  Al  Al10  1  0.942  0.889  0.890  1.0
  Al  Al11  1  0.288  0.557  0.575  1.0
  Si  Si12  1  0.989  0.230  0.375  1.0
  Si  Si13  1  0.011  0.770  0.625  1.0
  Si  Si14  1  0.253  0.457  0.079  1.0
  Si  Si15  1  0.747  0.543  0.921  1.0
  Si  Si16  1  0.770  0.011  0.125  1.0
  Si  Si17  1  0.230  0.989  0.875  1.0
  Si  Si18  1  0.543  0.747  0.421  1.0
  Si  Si19  1  0.457  0.253  0.579  1.0
  O  O20  1  0.628  0.690  0.875  1.0
  O  O21  1  0.884  0.130  0.078  1.0
  O  O22  1  0.568  0.351  0.466  1.0
  O  O23  1  0.310  0.372  0.625  1.0
  O  O24  1  0.468  0.837  0.303  1.0
  O  O25  1  0.896  0.391  0.387  1.0
  O  O26  1  0.649  0.432  0.034  1.0
  O  O27  1  0.069  0.867  0.318  1.0
  O  O28  1  0.130  0.884  0.578  1.0
  O  O29  1  0.123  0.185  0.462  1.0
  O  O30  1  0.432  0.649  0.534  1.0
  O  O31  1  0.218  0.072  0.724  1.0
  O  O32  1  0.690  0.628  0.375  1.0
  O  O33  1  0.815  0.877  0.038  1.0
  O  O34  1  0.609  0.104  0.113  1.0
  O  O35  1  0.072  0.218  0.224  1.0
  O  O36  1  0.532  0.163  0.697  1.0
  O  O37  1  0.351  0.568  0.966  1.0
  O  O38  1  0.391  0.896  0.887  1.0
  O  O39  1  0.372  0.310  0.125  1.0
  O  O40  1  0.877  0.815  0.538  1.0
  O  O41  1  0.870  0.116  0.422  1.0
  O  O42  1  0.928  0.782  0.776  1.0
  O  O43  1  0.782  0.928  0.276  1.0
  O  O44  1  0.163  0.532  0.197  1.0
  O  O45  1  0.116  0.870  0.922  1.0
  O  O46  1  0.104  0.609  0.613  1.0
  O  O47  1  0.867  0.069  0.818  1.0
  O  O48  1  0.931  0.133  0.682  1.0
  O  O49  1  0.837  0.468  0.803  1.0
  O  O50  1  0.185  0.123  0.962  1.0
  O  O51  1  0.133  0.931  0.182  1.0
[/CIF]
.