The material structure described by RbAlAs2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), two equivalent O(5), and two equivalent O(7) atoms. In the second Rb site, Rb(2) is bonded to two equivalent O(1), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms to form distorted RbO8 hexagonal bipyramids that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent As(1)O4 tetrahedra, corners with four equivalent As(2)O4 tetrahedra, edges with two equivalent Al(1)O6 octahedra, and edges with two equivalent As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. Al(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form AlO6 octahedra that share  a cornercorner with one Rb(2)O8 hexagonal bipyramid, corners with three equivalent As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra, and  an edgeedge with one Rb(2)O8 hexagonal bipyramid. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one Rb(2)O8 hexagonal bipyramid, corners with three equivalent Al(1)O6 octahedra,  a cornercorner with one As(2)O4 tetrahedra, and  an edgeedge with one Rb(2)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 40-49°. In the second As site, As(2) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form AsO4 tetrahedra that share corners with two equivalent Rb(2)O8 hexagonal bipyramids, corners with three equivalent Al(1)O6 octahedra, and  a cornercorner with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-51°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Rb(1), one Rb(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 Rb(2), one Al(1), and one As(2) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Al(1), and one As(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Rb(1), one Al(1), and one As(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Al(1), and one As(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Rb(2), one As(1), and one As(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Al(1), and one As(1) atom. is represented by the CIF file [CIF]
data_RbAlAs2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.263
_cell_length_b   6.359
_cell_length_c   8.255
_cell_angle_alpha   96.560
_cell_angle_beta   104.106
_cell_angle_gamma   102.579
_symmetry_Int_Tables_number   1
_cell_volume   306.318
_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
  Rb  Rb0  1  0.000  0.000  0.000  1.0
  Rb  Rb1  1  0.000  0.000  0.500  1.0
  Al  Al2  1  0.623  0.313  0.771  1.0
  Al  Al3  1  0.377  0.687  0.229  1.0
  As  As4  1  0.176  0.472  0.814  1.0
  As  As5  1  0.824  0.528  0.186  1.0
  As  As6  1  0.508  0.757  0.664  1.0
  As  As7  1  0.492  0.243  0.336  1.0
  O  O8  1  0.336  0.292  0.815  1.0
  O  O9  1  0.469  0.255  0.534  1.0
  O  O10  1  0.579  0.011  0.772  1.0
  O  O11  1  0.327  0.380  0.221  1.0
  O  O12  1  0.092  0.678  0.273  1.0
  O  O13  1  0.908  0.322  0.727  1.0
  O  O14  1  0.421  0.989  0.228  1.0
  O  O15  1  0.664  0.708  0.185  1.0
  O  O16  1  0.531  0.745  0.466  1.0
  O  O17  1  0.777  0.361  0.340  1.0
  O  O18  1  0.673  0.620  0.779  1.0
  O  O19  1  0.223  0.639  0.660  1.0
  O  O20  1  0.224  0.647  0.993  1.0
  O  O21  1  0.776  0.353  0.007  1.0
[/CIF]
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The material structure described by RbAlAs2O7 crystallizes in the triclinic P-1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), two equivalent O(5), and two equivalent O(7) atoms. In the second Rb site, Rb(2) is bonded to two equivalent O(1), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms to form distorted RbO8 hexagonal bipyramids that share corners with two equivalent Al(1)O6 octahedra, corners with two equivalent As(1)O4 tetrahedra, corners with four equivalent As(2)O4 tetrahedra, edges with two equivalent Al(1)O6 octahedra, and edges with two equivalent As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. Al(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(7) atom to form AlO6 octahedra that share  a cornercorner with one Rb(2)O8 hexagonal bipyramid, corners with three equivalent As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra, and  an edgeedge with one Rb(2)O8 hexagonal bipyramid. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(5), one O(6), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one Rb(2)O8 hexagonal bipyramid, corners with three equivalent Al(1)O6 octahedra,  a cornercorner with one As(2)O4 tetrahedra, and  an edgeedge with one Rb(2)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 40-49°. In the second As site, As(2) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form AsO4 tetrahedra that share corners with two equivalent Rb(2)O8 hexagonal bipyramids, corners with three equivalent Al(1)O6 octahedra, and  a cornercorner with one As(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 31-51°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Rb(1), one Rb(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 Rb(2), one Al(1), and one As(2) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Al(1), and one As(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Rb(1), one Al(1), and one As(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Al(1), and one As(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Rb(2), one As(1), and one As(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Al(1), and one As(1) atom. is represented by the CIF file [CIF]
data_RbAlAs2O7
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.263
_cell_length_b   6.359
_cell_length_c   8.255
_cell_angle_alpha   96.560
_cell_angle_beta   104.106
_cell_angle_gamma   102.579
_symmetry_Int_Tables_number   1
_cell_volume   306.318
_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
  Rb  Rb0  1  0.000  0.000  0.000  1.0
  Rb  Rb1  1  0.000  0.000  0.500  1.0
  Al  Al2  1  0.623  0.313  0.771  1.0
  Al  Al3  1  0.377  0.687  0.229  1.0
  As  As4  1  0.176  0.472  0.814  1.0
  As  As5  1  0.824  0.528  0.186  1.0
  As  As6  1  0.508  0.757  0.664  1.0
  As  As7  1  0.492  0.243  0.336  1.0
  O  O8  1  0.336  0.292  0.815  1.0
  O  O9  1  0.469  0.255  0.534  1.0
  O  O10  1  0.579  0.011  0.772  1.0
  O  O11  1  0.327  0.380  0.221  1.0
  O  O12  1  0.092  0.678  0.273  1.0
  O  O13  1  0.908  0.322  0.727  1.0
  O  O14  1  0.421  0.989  0.228  1.0
  O  O15  1  0.664  0.708  0.185  1.0
  O  O16  1  0.531  0.745  0.466  1.0
  O  O17  1  0.777  0.361  0.340  1.0
  O  O18  1  0.673  0.620  0.779  1.0
  O  O19  1  0.223  0.639  0.660  1.0
  O  O20  1  0.224  0.647  0.993  1.0
  O  O21  1  0.776  0.353  0.007  1.0
[/CIF]
.