The material described by KAsO3 crystallizes in the triclinic P-1 space group. There are three inequivalent K sites. In the first K site, K(1) is bonded to one O(1), one O(5), one O(8), one O(9), and two equivalent O(2) atoms to form KO6 octahedra that share  a cornercorner with one As(2)O4 tetrahedra, corners with two equivalent As(3)O4 tetrahedra, corners with three equivalent As(1)O4 tetrahedra, and  an edgeedge with one K(1)O6 octahedra. In the second K site, K(2) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(7), one O(8), two equivalent O(5), and two equivalent O(6) atoms. In the third K site, K(3) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(6), one O(8), and two equivalent O(9) atoms. There are three inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with three equivalent K(1)O6 octahedra,  a cornercorner with one As(2)O4 tetrahedra, and  a cornercorner with one As(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-58°. In the second As site, As(2) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one K(1)O6 octahedra,  a cornercorner with one As(1)O4 tetrahedra, and  a cornercorner with one As(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. In the third As site, As(3) is bonded to one O(4), one O(7), one O(8), and one O(9) atom to form AsO4 tetrahedra that share corners with two equivalent K(1)O6 octahedra,  a cornercorner with one As(1)O4 tetrahedra, and  a cornercorner with one As(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-58°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one K(1), one K(2), one K(3), and one As(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one K(3), two equivalent K(1), and one As(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one K(2), one As(1), and one As(2) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one As(1) and one As(3) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one K(1), two equivalent K(2), and one As(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one K(3), two equivalent K(2), and one As(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one K(2), one As(2), and one As(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one K(1), one K(2), one K(3), and one As(3) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one K(1), two equivalent K(3), and one As(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_KAsO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.560
_cell_length_b   7.563
_cell_length_c   10.320
_cell_angle_alpha   85.729
_cell_angle_beta   111.250
_cell_angle_gamma   106.861
_symmetry_Int_Tables_number   1
_cell_volume   525.978
_cell_formula_units_Z   6
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
  K  K0  1  0.090  0.105  0.838  1.0
  K  K1  1  0.910  0.895  0.162  1.0
  K  K2  1  0.246  0.238  0.503  1.0
  K  K3  1  0.754  0.762  0.497  1.0
  K  K4  1  0.726  0.460  0.835  1.0
  K  K5  1  0.274  0.540  0.165  1.0
  As  As6  1  0.529  0.981  0.801  1.0
  As  As7  1  0.471  0.019  0.199  1.0
  As  As8  1  0.271  0.736  0.525  1.0
  As  As9  1  0.729  0.264  0.475  1.0
  As  As10  1  0.169  0.641  0.795  1.0
  As  As11  1  0.831  0.359  0.205  1.0
  O  O12  1  0.408  0.139  0.765  1.0
  O  O13  1  0.592  0.861  0.235  1.0
  O  O14  1  0.765  0.039  0.898  1.0
  O  O15  1  0.235  0.961  0.102  1.0
  O  O16  1  0.502  0.873  0.644  1.0
  O  O17  1  0.498  0.127  0.356  1.0
  O  O18  1  0.411  0.788  0.880  1.0
  O  O19  1  0.589  0.212  0.120  1.0
  O  O20  1  0.115  0.860  0.457  1.0
  O  O21  1  0.885  0.140  0.543  1.0
  O  O22  1  0.334  0.618  0.429  1.0
  O  O23  1  0.666  0.382  0.571  1.0
  O  O24  1  0.194  0.572  0.642  1.0
  O  O25  1  0.806  0.428  0.358  1.0
  O  O26  1  1.000  0.753  0.755  1.0
  O  O27  1  0.000  0.247  0.245  1.0
  O  O28  1  0.143  0.459  0.892  1.0
  O  O29  1  0.857  0.541  0.108  1.0
[/CIF]
.
The material described by KAsO3 crystallizes in the triclinic P-1 space group. There are three inequivalent K sites. In the first K site, K(1) is bonded to one O(1), one O(5), one O(8), one O(9), and two equivalent O(2) atoms to form KO6 octahedra that share  a cornercorner with one As(2)O4 tetrahedra, corners with two equivalent As(3)O4 tetrahedra, corners with three equivalent As(1)O4 tetrahedra, and  an edgeedge with one K(1)O6 octahedra. In the second K site, K(2) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(7), one O(8), two equivalent O(5), and two equivalent O(6) atoms. In the third K site, K(3) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(6), one O(8), and two equivalent O(9) atoms. There are three inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with three equivalent K(1)O6 octahedra,  a cornercorner with one As(2)O4 tetrahedra, and  a cornercorner with one As(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-58°. In the second As site, As(2) is bonded to one O(3), one O(5), one O(6), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one K(1)O6 octahedra,  a cornercorner with one As(1)O4 tetrahedra, and  a cornercorner with one As(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 54°. In the third As site, As(3) is bonded to one O(4), one O(7), one O(8), and one O(9) atom to form AsO4 tetrahedra that share corners with two equivalent K(1)O6 octahedra,  a cornercorner with one As(1)O4 tetrahedra, and  a cornercorner with one As(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-58°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one K(1), one K(2), one K(3), and one As(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one K(3), two equivalent K(1), and one As(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one K(2), one As(1), and one As(2) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one As(1) and one As(3) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one K(1), two equivalent K(2), and one As(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one K(3), two equivalent K(2), and one As(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one K(2), one As(2), and one As(3) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one K(1), one K(2), one K(3), and one As(3) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one K(1), two equivalent K(3), and one As(3) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_KAsO3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.560
_cell_length_b   7.563
_cell_length_c   10.320
_cell_angle_alpha   85.729
_cell_angle_beta   111.250
_cell_angle_gamma   106.861
_symmetry_Int_Tables_number   1
_cell_volume   525.978
_cell_formula_units_Z   6
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
  K  K0  1  0.090  0.105  0.838  1.0
  K  K1  1  0.910  0.895  0.162  1.0
  K  K2  1  0.246  0.238  0.503  1.0
  K  K3  1  0.754  0.762  0.497  1.0
  K  K4  1  0.726  0.460  0.835  1.0
  K  K5  1  0.274  0.540  0.165  1.0
  As  As6  1  0.529  0.981  0.801  1.0
  As  As7  1  0.471  0.019  0.199  1.0
  As  As8  1  0.271  0.736  0.525  1.0
  As  As9  1  0.729  0.264  0.475  1.0
  As  As10  1  0.169  0.641  0.795  1.0
  As  As11  1  0.831  0.359  0.205  1.0
  O  O12  1  0.408  0.139  0.765  1.0
  O  O13  1  0.592  0.861  0.235  1.0
  O  O14  1  0.765  0.039  0.898  1.0
  O  O15  1  0.235  0.961  0.102  1.0
  O  O16  1  0.502  0.873  0.644  1.0
  O  O17  1  0.498  0.127  0.356  1.0
  O  O18  1  0.411  0.788  0.880  1.0
  O  O19  1  0.589  0.212  0.120  1.0
  O  O20  1  0.115  0.860  0.457  1.0
  O  O21  1  0.885  0.140  0.543  1.0
  O  O22  1  0.334  0.618  0.429  1.0
  O  O23  1  0.666  0.382  0.571  1.0
  O  O24  1  0.194  0.572  0.642  1.0
  O  O25  1  0.806  0.428  0.358  1.0
  O  O26  1  1.000  0.753  0.755  1.0
  O  O27  1  0.000  0.247  0.245  1.0
  O  O28  1  0.143  0.459  0.892  1.0
  O  O29  1  0.857  0.541  0.108  1.0
[/CIF]
.