The compound described by W2Al2O7 crystallizes in the triclinic P1 space group. There are four inequivalent W sites. In the first W site, W(1) is bonded in a 6-coordinate geometry to one O(10), one O(14), one O(4), one O(5), one O(7), and one O(9) atom. In the second W site, W(2) is bonded to one O(10), one O(12), one O(13), one O(3), one O(7), and one O(8) atom to form distorted WO6 octahedra that share  a cornercorner with one Al(4)O4 tetrahedra, corners with two equivalent Al(3)O5 trigonal bipyramids,  an edgeedge with one Al(4)O4 tetrahedra, and  an edgeedge with one Al(1)O5 trigonal bipyramid. In the third W site, W(3) is bonded in a 5-coordinate geometry to one O(13), one O(4), one O(6), one O(8), and one O(9) atom. In the fourth W site, W(4) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(14), one O(5), and one O(6) atom. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(11), one O(13), one O(2), and one O(3) atom to form distorted AlO5 trigonal bipyramids that share  a cornercorner with one Al(4)O4 tetrahedra,  a cornercorner with one Al(3)O5 trigonal bipyramid,  an edgeedge with one W(2)O6 octahedra,  an edgeedge with one Al(2)O5 trigonal bipyramid, and  an edgeedge with one Al(3)O5 trigonal bipyramid. In the second Al site, Al(2) is bonded to one O(11), one O(14), one O(2), one O(6), and one O(9) atom to form a mixture of corner and edge-sharing AlO5 trigonal bipyramids. In the third Al site, Al(3) is bonded to one O(1), one O(12), one O(2), one O(3), and one O(5) atom to form AlO5 trigonal bipyramids that share corners with two equivalent W(2)O6 octahedra,  a cornercorner with one Al(4)O4 tetrahedra,  a cornercorner with one Al(1)O5 trigonal bipyramid,  a cornercorner with one Al(2)O5 trigonal bipyramid, and  an edgeedge with one Al(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 55°. In the fourth Al site, Al(4) is bonded to one O(1), one O(10), one O(7), and one O(8) atom to form distorted AlO4 tetrahedra that share  a cornercorner with one W(2)O6 octahedra,  a cornercorner with one Al(1)O5 trigonal bipyramid,  a cornercorner with one Al(3)O5 trigonal bipyramid, and  an edgeedge with one W(2)O6 octahedra. The corner-sharing octahedral tilt angles are 60°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Al(1), one Al(3), and one Al(4) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(2), and one Al(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one W(2), one Al(1), and one Al(3) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one W(1) and one W(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one W(1), one W(4), and one Al(3) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one W(3), one W(4), and one Al(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one W(1), one W(2), and one Al(4) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one W(2), one W(3), and one Al(4) atom. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one W(1), one W(3), and one Al(2) atom. In the tenth O site, O(10) is bonded in a distorted trigonal non-coplanar geometry to one W(1), one W(2), and one Al(4) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one W(4), one Al(1), and one Al(2) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one W(2), one W(4), and one Al(3) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one W(2), one W(3), and one Al(1) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one W(1), one W(4), and one Al(2) atom. is represented by the CIF card [CIF]
data_Al2W2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.801
_cell_length_b   7.185
_cell_length_c   7.718
_cell_angle_alpha   49.805
_cell_angle_beta   57.252
_cell_angle_gamma   55.573
_symmetry_Int_Tables_number   1
_cell_volume   261.713
_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  0.443  0.036  0.598  1.0
  Al  Al1  1  0.116  0.444  0.370  1.0
  Al  Al2  1  0.545  0.485  0.986  1.0
  Al  Al3  1  0.484  0.609  0.525  1.0
  W  W4  1  0.985  0.504  0.018  1.0
  W  W5  1  0.502  1.000  0.989  1.0
  W  W6  1  0.964  0.978  0.464  1.0
  W  W7  1  0.968  0.024  0.000  1.0
  O  O8  1  0.539  0.704  0.653  1.0
  O  O9  1  0.407  0.308  0.294  1.0
  O  O10  1  0.391  0.831  0.958  1.0
  O  O11  1  0.986  0.633  0.708  1.0
  O  O12  1  0.801  0.338  0.069  1.0
  O  O13  1  0.984  0.776  0.332  1.0
  O  O14  1  0.336  0.384  0.810  1.0
  O  O15  1  0.302  0.875  0.345  1.0
  O  O16  1  0.982  0.284  0.390  1.0
  O  O17  1  0.686  0.667  0.213  1.0
  O  O18  1  0.147  0.190  0.671  1.0
  O  O19  1  0.678  0.175  0.957  1.0
  O  O20  1  0.636  0.099  0.611  1.0
  O  O21  1  0.117  0.655  0.036  1.0
[/CIF]
.
The compound described by W2Al2O7 crystallizes in the triclinic P1 space group. There are four inequivalent W sites. In the first W site, W(1) is bonded in a 6-coordinate geometry to one O(10), one O(14), one O(4), one O(5), one O(7), and one O(9) atom. In the second W site, W(2) is bonded to one O(10), one O(12), one O(13), one O(3), one O(7), and one O(8) atom to form distorted WO6 octahedra that share  a cornercorner with one Al(4)O4 tetrahedra, corners with two equivalent Al(3)O5 trigonal bipyramids,  an edgeedge with one Al(4)O4 tetrahedra, and  an edgeedge with one Al(1)O5 trigonal bipyramid. In the third W site, W(3) is bonded in a 5-coordinate geometry to one O(13), one O(4), one O(6), one O(8), and one O(9) atom. In the fourth W site, W(4) is bonded in a 5-coordinate geometry to one O(11), one O(12), one O(14), one O(5), and one O(6) atom. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(11), one O(13), one O(2), and one O(3) atom to form distorted AlO5 trigonal bipyramids that share  a cornercorner with one Al(4)O4 tetrahedra,  a cornercorner with one Al(3)O5 trigonal bipyramid,  an edgeedge with one W(2)O6 octahedra,  an edgeedge with one Al(2)O5 trigonal bipyramid, and  an edgeedge with one Al(3)O5 trigonal bipyramid. In the second Al site, Al(2) is bonded to one O(11), one O(14), one O(2), one O(6), and one O(9) atom to form a mixture of corner and edge-sharing AlO5 trigonal bipyramids. In the third Al site, Al(3) is bonded to one O(1), one O(12), one O(2), one O(3), and one O(5) atom to form AlO5 trigonal bipyramids that share corners with two equivalent W(2)O6 octahedra,  a cornercorner with one Al(4)O4 tetrahedra,  a cornercorner with one Al(1)O5 trigonal bipyramid,  a cornercorner with one Al(2)O5 trigonal bipyramid, and  an edgeedge with one Al(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 55°. In the fourth Al site, Al(4) is bonded to one O(1), one O(10), one O(7), and one O(8) atom to form distorted AlO4 tetrahedra that share  a cornercorner with one W(2)O6 octahedra,  a cornercorner with one Al(1)O5 trigonal bipyramid,  a cornercorner with one Al(3)O5 trigonal bipyramid, and  an edgeedge with one W(2)O6 octahedra. The corner-sharing octahedral tilt angles are 60°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Al(1), one Al(3), and one Al(4) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Al(1), one Al(2), and one Al(3) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one W(2), one Al(1), and one Al(3) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one W(1) and one W(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one W(1), one W(4), and one Al(3) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one W(3), one W(4), and one Al(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one W(1), one W(2), and one Al(4) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one W(2), one W(3), and one Al(4) atom. In the ninth O site, O(9) is bonded in a distorted T-shaped geometry to one W(1), one W(3), and one Al(2) atom. In the tenth O site, O(10) is bonded in a distorted trigonal non-coplanar geometry to one W(1), one W(2), and one Al(4) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one W(4), one Al(1), and one Al(2) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one W(2), one W(4), and one Al(3) atom. In the thirteenth O site, O(13) is bonded in a distorted trigonal planar geometry to one W(2), one W(3), and one Al(1) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal non-coplanar geometry to one W(1), one W(4), and one Al(2) atom. is represented by the CIF card [CIF]
data_Al2W2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.801
_cell_length_b   7.185
_cell_length_c   7.718
_cell_angle_alpha   49.805
_cell_angle_beta   57.252
_cell_angle_gamma   55.573
_symmetry_Int_Tables_number   1
_cell_volume   261.713
_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  0.443  0.036  0.598  1.0
  Al  Al1  1  0.116  0.444  0.370  1.0
  Al  Al2  1  0.545  0.485  0.986  1.0
  Al  Al3  1  0.484  0.609  0.525  1.0
  W  W4  1  0.985  0.504  0.018  1.0
  W  W5  1  0.502  1.000  0.989  1.0
  W  W6  1  0.964  0.978  0.464  1.0
  W  W7  1  0.968  0.024  0.000  1.0
  O  O8  1  0.539  0.704  0.653  1.0
  O  O9  1  0.407  0.308  0.294  1.0
  O  O10  1  0.391  0.831  0.958  1.0
  O  O11  1  0.986  0.633  0.708  1.0
  O  O12  1  0.801  0.338  0.069  1.0
  O  O13  1  0.984  0.776  0.332  1.0
  O  O14  1  0.336  0.384  0.810  1.0
  O  O15  1  0.302  0.875  0.345  1.0
  O  O16  1  0.982  0.284  0.390  1.0
  O  O17  1  0.686  0.667  0.213  1.0
  O  O18  1  0.147  0.190  0.671  1.0
  O  O19  1  0.678  0.175  0.957  1.0
  O  O20  1  0.636  0.099  0.611  1.0
  O  O21  1  0.117  0.655  0.036  1.0
[/CIF]
.