The material structure described by Cs2Al2As2O7 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(1) atoms. In the second Cs site, Cs(2) is bonded to four equivalent O(1) and four equivalent O(3) atoms to form distorted CsO8 hexagonal bipyramids that share corners with four equivalent Al(1)O4 tetrahedra, edges with two equivalent Cs(2)O8 hexagonal bipyramids, and edges with two equivalent Al(1)O4 tetrahedra. Al(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form AlO4 tetrahedra that share corners with two equivalent Cs(2)O8 hexagonal bipyramids,  a cornercorner with one Al(1)O4 tetrahedra, and  an edgeedge with one Cs(2)O8 hexagonal bipyramid. As(1) is bonded in a 3-coordinate geometry to one O(3) and two equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Cs(1), one Cs(2), one Al(1), and one As(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cs(1) and two equivalent Al(1) atoms. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to two equivalent Cs(2), one Al(1), and one As(1) atom. is represented by the CIF card [CIF]
data_Cs2Al2As2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.348
_cell_length_b   7.348
_cell_length_c   7.348
_cell_angle_alpha   135.521
_cell_angle_beta   103.990
_cell_angle_gamma   92.565
_symmetry_Int_Tables_number   1
_cell_volume   255.625
_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
  Cs  Cs0  1  0.344  0.000  0.344  1.0
  Cs  Cs1  1  0.699  0.500  0.199  1.0
  Al  Al2  1  0.776  0.838  0.938  1.0
  Al  Al3  1  0.100  0.162  0.938  1.0
  As  As4  1  0.316  0.700  0.616  1.0
  As  As5  1  0.916  0.300  0.616  1.0
  O  O6  1  0.253  0.997  0.744  1.0
  O  O7  1  0.000  0.000  0.000  1.0
  O  O8  1  0.578  0.838  0.740  1.0
  O  O9  1  0.253  0.509  0.256  1.0
  O  O10  1  0.746  0.003  0.256  1.0
  O  O11  1  0.746  0.491  0.744  1.0
  O  O12  1  0.902  0.162  0.740  1.0
[/CIF]
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The material structure described by Cs2Al2As2O7 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(1) atoms. In the second Cs site, Cs(2) is bonded to four equivalent O(1) and four equivalent O(3) atoms to form distorted CsO8 hexagonal bipyramids that share corners with four equivalent Al(1)O4 tetrahedra, edges with two equivalent Cs(2)O8 hexagonal bipyramids, and edges with two equivalent Al(1)O4 tetrahedra. Al(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form AlO4 tetrahedra that share corners with two equivalent Cs(2)O8 hexagonal bipyramids,  a cornercorner with one Al(1)O4 tetrahedra, and  an edgeedge with one Cs(2)O8 hexagonal bipyramid. As(1) is bonded in a 3-coordinate geometry to one O(3) and two equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Cs(1), one Cs(2), one Al(1), and one As(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Cs(1) and two equivalent Al(1) atoms. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to two equivalent Cs(2), one Al(1), and one As(1) atom. is represented by the CIF card [CIF]
data_Cs2Al2As2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.348
_cell_length_b   7.348
_cell_length_c   7.348
_cell_angle_alpha   135.521
_cell_angle_beta   103.990
_cell_angle_gamma   92.565
_symmetry_Int_Tables_number   1
_cell_volume   255.625
_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
  Cs  Cs0  1  0.344  0.000  0.344  1.0
  Cs  Cs1  1  0.699  0.500  0.199  1.0
  Al  Al2  1  0.776  0.838  0.938  1.0
  Al  Al3  1  0.100  0.162  0.938  1.0
  As  As4  1  0.316  0.700  0.616  1.0
  As  As5  1  0.916  0.300  0.616  1.0
  O  O6  1  0.253  0.997  0.744  1.0
  O  O7  1  0.000  0.000  0.000  1.0
  O  O8  1  0.578  0.838  0.740  1.0
  O  O9  1  0.253  0.509  0.256  1.0
  O  O10  1  0.746  0.003  0.256  1.0
  O  O11  1  0.746  0.491  0.744  1.0
  O  O12  1  0.902  0.162  0.740  1.0
[/CIF]
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