The compound described by Mo2Al2O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms. In the second Mo site, Mo(2) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(7) atoms to form MoO6 octahedra that share corners with two equivalent Mo(3)O6 octahedra, corners with two equivalent Al(3)O6 octahedra, and edges with two equivalent Al(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-64°. In the third Mo site, Mo(3) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(7) atoms to form distorted MoO6 octahedra that share corners with two equivalent Mo(2)O6 octahedra, corners with two equivalent Al(4)O6 octahedra, and edges with two equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-58°. In the fourth Mo site, Mo(4) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms. In the second Al site, Al(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form distorted AlO6 octahedra that share corners with two equivalent Al(3)O6 octahedra, corners with two equivalent Al(4)O6 octahedra, and edges with two equivalent Mo(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 66-75°. In the third Al site, Al(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted AlO6 octahedra that share corners with two equivalent Mo(2)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, and corners with two equivalent Al(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 64-75°. In the fourth Al site, Al(4) is bonded to two equivalent O(1), two equivalent O(6), and two equivalent O(7) atoms to form AlO6 octahedra that share corners with two equivalent Mo(3)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, corners with two equivalent Al(3)O6 octahedra, and edges with two equivalent Mo(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-66°. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Al(1), one Al(2), one Al(3), and one Al(4) atom to form OAl4 tetrahedra that share corners with two equivalent O(2)Al2Mo2 tetrahedra, corners with two equivalent O(5)Al2Mo2 tetrahedra, corners with four equivalent O(1)Al4 tetrahedra,  an edgeedge with one O(2)Al2Mo2 tetrahedra, and  an edgeedge with one O(5)Al2Mo2 tetrahedra. In the second O site, O(2) is bonded to one Mo(2), one Mo(4), one Al(1), and one Al(3) atom to form distorted OAl2Mo2 tetrahedra that share corners with two equivalent O(5)Al2Mo2 tetrahedra, corners with two equivalent O(1)Al4 tetrahedra, corners with four equivalent O(2)Al2Mo2 tetrahedra,  an edgeedge with one O(5)Al2Mo2 tetrahedra, and  an edgeedge with one O(1)Al4 tetrahedra. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mo(1), one Mo(3), and one Al(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Mo(1), one Mo(4), and one Al(3) atom. In the fifth O site, O(5) is bonded to one Mo(3), one Mo(4), one Al(1), and one Al(2) atom to form OAl2Mo2 tetrahedra that share corners with two equivalent O(2)Al2Mo2 tetrahedra, corners with two equivalent O(1)Al4 tetrahedra, corners with four equivalent O(5)Al2Mo2 tetrahedra,  an edgeedge with one O(2)Al2Mo2 tetrahedra, and  an edgeedge with one O(1)Al4 tetrahedra. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Mo(1), one Mo(2), and one Al(4) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Mo(2), one Mo(3), and one Al(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Al2Mo2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.682
_cell_length_b   6.751
_cell_length_c   6.767
_cell_angle_alpha   66.110
_cell_angle_beta   65.969
_cell_angle_gamma   65.332
_symmetry_Int_Tables_number   1
_cell_volume   242.977
_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  0.500  0.000  0.500  1.0
  Al  Al1  1  0.500  0.000  0.000  1.0
  Al  Al2  1  0.000  0.000  0.500  1.0
  Al  Al3  1  0.500  0.500  0.500  1.0
  Mo  Mo4  1  0.000  0.500  0.000  1.0
  Mo  Mo5  1  0.000  0.500  0.500  1.0
  Mo  Mo6  1  0.500  0.500  0.000  1.0
  Mo  Mo7  1  0.000  0.000  0.000  1.0
  O  O8  1  0.611  0.153  0.607  1.0
  O  O9  1  0.389  0.847  0.393  1.0
  O  O10  1  0.883  0.844  0.405  1.0
  O  O11  1  0.680  0.684  0.988  1.0
  O  O12  1  0.991  0.837  0.821  1.0
  O  O13  1  0.346  0.883  0.896  1.0
  O  O14  1  0.829  0.506  0.318  1.0
  O  O15  1  0.356  0.478  0.320  1.0
  O  O16  1  0.320  0.316  0.012  1.0
  O  O17  1  0.171  0.494  0.682  1.0
  O  O18  1  0.654  0.117  0.104  1.0
  O  O19  1  0.117  0.156  0.595  1.0
  O  O20  1  0.644  0.522  0.680  1.0
  O  O21  1  0.009  0.163  0.179  1.0
[/CIF]
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The compound described by Mo2Al2O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Mo sites. In the first Mo site, Mo(1) is bonded in a 6-coordinate geometry to two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms. In the second Mo site, Mo(2) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(7) atoms to form MoO6 octahedra that share corners with two equivalent Mo(3)O6 octahedra, corners with two equivalent Al(3)O6 octahedra, and edges with two equivalent Al(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-64°. In the third Mo site, Mo(3) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(7) atoms to form distorted MoO6 octahedra that share corners with two equivalent Mo(2)O6 octahedra, corners with two equivalent Al(4)O6 octahedra, and edges with two equivalent Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-58°. In the fourth Mo site, Mo(4) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms. In the second Al site, Al(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form distorted AlO6 octahedra that share corners with two equivalent Al(3)O6 octahedra, corners with two equivalent Al(4)O6 octahedra, and edges with two equivalent Mo(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 66-75°. In the third Al site, Al(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form distorted AlO6 octahedra that share corners with two equivalent Mo(2)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, and corners with two equivalent Al(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 64-75°. In the fourth Al site, Al(4) is bonded to two equivalent O(1), two equivalent O(6), and two equivalent O(7) atoms to form AlO6 octahedra that share corners with two equivalent Mo(3)O6 octahedra, corners with two equivalent Al(2)O6 octahedra, corners with two equivalent Al(3)O6 octahedra, and edges with two equivalent Mo(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 58-66°. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Al(1), one Al(2), one Al(3), and one Al(4) atom to form OAl4 tetrahedra that share corners with two equivalent O(2)Al2Mo2 tetrahedra, corners with two equivalent O(5)Al2Mo2 tetrahedra, corners with four equivalent O(1)Al4 tetrahedra,  an edgeedge with one O(2)Al2Mo2 tetrahedra, and  an edgeedge with one O(5)Al2Mo2 tetrahedra. In the second O site, O(2) is bonded to one Mo(2), one Mo(4), one Al(1), and one Al(3) atom to form distorted OAl2Mo2 tetrahedra that share corners with two equivalent O(5)Al2Mo2 tetrahedra, corners with two equivalent O(1)Al4 tetrahedra, corners with four equivalent O(2)Al2Mo2 tetrahedra,  an edgeedge with one O(5)Al2Mo2 tetrahedra, and  an edgeedge with one O(1)Al4 tetrahedra. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mo(1), one Mo(3), and one Al(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Mo(1), one Mo(4), and one Al(3) atom. In the fifth O site, O(5) is bonded to one Mo(3), one Mo(4), one Al(1), and one Al(2) atom to form OAl2Mo2 tetrahedra that share corners with two equivalent O(2)Al2Mo2 tetrahedra, corners with two equivalent O(1)Al4 tetrahedra, corners with four equivalent O(5)Al2Mo2 tetrahedra,  an edgeedge with one O(2)Al2Mo2 tetrahedra, and  an edgeedge with one O(1)Al4 tetrahedra. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Mo(1), one Mo(2), and one Al(4) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Mo(2), one Mo(3), and one Al(4) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Al2Mo2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.682
_cell_length_b   6.751
_cell_length_c   6.767
_cell_angle_alpha   66.110
_cell_angle_beta   65.969
_cell_angle_gamma   65.332
_symmetry_Int_Tables_number   1
_cell_volume   242.977
_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  0.500  0.000  0.500  1.0
  Al  Al1  1  0.500  0.000  0.000  1.0
  Al  Al2  1  0.000  0.000  0.500  1.0
  Al  Al3  1  0.500  0.500  0.500  1.0
  Mo  Mo4  1  0.000  0.500  0.000  1.0
  Mo  Mo5  1  0.000  0.500  0.500  1.0
  Mo  Mo6  1  0.500  0.500  0.000  1.0
  Mo  Mo7  1  0.000  0.000  0.000  1.0
  O  O8  1  0.611  0.153  0.607  1.0
  O  O9  1  0.389  0.847  0.393  1.0
  O  O10  1  0.883  0.844  0.405  1.0
  O  O11  1  0.680  0.684  0.988  1.0
  O  O12  1  0.991  0.837  0.821  1.0
  O  O13  1  0.346  0.883  0.896  1.0
  O  O14  1  0.829  0.506  0.318  1.0
  O  O15  1  0.356  0.478  0.320  1.0
  O  O16  1  0.320  0.316  0.012  1.0
  O  O17  1  0.171  0.494  0.682  1.0
  O  O18  1  0.654  0.117  0.104  1.0
  O  O19  1  0.117  0.156  0.595  1.0
  O  O20  1  0.644  0.522  0.680  1.0
  O  O21  1  0.009  0.163  0.179  1.0
[/CIF]
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