The crystal structure described by K3Bi2(AsO4)3 is Esseneite-like structured and crystallizes in the monoclinic C2/c space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent O(4), two equivalent O(5), and four equivalent O(6) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. In the third K site, K(3) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form KO6 octahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with two equivalent As(2)O4 tetrahedra, corners with four equivalent As(1)O4 tetrahedra, and edges with two equivalent K(3)O6 octahedra. The corner-sharing octahedral tilt angles are 81°. Bi(1) is bonded to one O(3), one O(4), one O(5), one O(6), and two equivalent O(2) atoms to form distorted BiO6 octahedra that share  a cornercorner with one K(3)O6 octahedra, corners with two equivalent As(2)O4 tetrahedra, corners with four equivalent As(1)O4 tetrahedra, and  an edgeedge with one Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles are 81°. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form AsO4 tetrahedra that share corners with two equivalent K(3)O6 octahedra and corners with four equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 19-66°. In the second As site, As(2) is bonded to two equivalent O(3) and two equivalent O(5) atoms to form AsO4 tetrahedra that share corners with two equivalent K(3)O6 octahedra and corners with four equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-60°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one K(2), two equivalent K(3), and one As(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Bi(1) and one As(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one K(2), one K(3), one Bi(1), and one As(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Bi(1), and one As(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Bi(1), and one As(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to two equivalent K(1), one Bi(1), and one As(1) atom. is represented by the CIF card [CIF]
data_K3Bi2(AsO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.998
_cell_length_b   9.998
_cell_length_c   7.177
_cell_angle_alpha   72.683
_cell_angle_beta   72.683
_cell_angle_gamma   89.284
_symmetry_Int_Tables_number   1
_cell_volume   651.653
_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
  K  K0  1  0.986  0.014  0.250  1.0
  K  K1  1  0.276  0.724  0.750  1.0
  K  K2  1  0.724  0.276  0.250  1.0
  K  K3  1  0.500  0.500  0.000  1.0
  K  K4  1  0.014  0.986  0.750  1.0
  K  K5  1  0.500  0.500  0.500  1.0
  Bi  Bi6  1  0.616  0.912  0.166  1.0
  Bi  Bi7  1  0.912  0.616  0.666  1.0
  Bi  Bi8  1  0.088  0.384  0.334  1.0
  Bi  Bi9  1  0.384  0.088  0.834  1.0
  As  As10  1  0.861  0.650  0.139  1.0
  As  As11  1  0.139  0.350  0.861  1.0
  As  As12  1  0.246  0.754  0.250  1.0
  As  As13  1  0.350  0.139  0.361  1.0
  As  As14  1  0.650  0.861  0.639  1.0
  As  As15  1  0.754  0.246  0.750  1.0
  O  O16  1  0.425  0.291  0.361  1.0
  O  O17  1  0.548  0.916  0.844  1.0
  O  O18  1  0.452  0.084  0.156  1.0
  O  O19  1  0.392  0.758  0.327  1.0
  O  O20  1  0.575  0.709  0.639  1.0
  O  O21  1  0.916  0.548  0.344  1.0
  O  O22  1  0.663  0.992  0.409  1.0
  O  O23  1  0.992  0.663  0.909  1.0
  O  O24  1  0.765  0.101  0.952  1.0
  O  O25  1  0.157  0.184  0.838  1.0
  O  O26  1  0.242  0.608  0.173  1.0
  O  O27  1  0.101  0.765  0.452  1.0
  O  O28  1  0.843  0.816  0.162  1.0
  O  O29  1  0.816  0.843  0.662  1.0
  O  O30  1  0.291  0.425  0.861  1.0
  O  O31  1  0.008  0.337  0.091  1.0
  O  O32  1  0.337  0.008  0.591  1.0
  O  O33  1  0.084  0.452  0.656  1.0
  O  O34  1  0.758  0.392  0.827  1.0
  O  O35  1  0.899  0.235  0.548  1.0
  O  O36  1  0.235  0.899  0.048  1.0
  O  O37  1  0.608  0.242  0.673  1.0
  O  O38  1  0.184  0.157  0.338  1.0
  O  O39  1  0.709  0.575  0.139  1.0
[/CIF]
.
The crystal structure described by K3Bi2(AsO4)3 is Esseneite-like structured and crystallizes in the monoclinic C2/c space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent O(4), two equivalent O(5), and four equivalent O(6) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. In the third K site, K(3) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form KO6 octahedra that share corners with two equivalent Bi(1)O6 octahedra, corners with two equivalent As(2)O4 tetrahedra, corners with four equivalent As(1)O4 tetrahedra, and edges with two equivalent K(3)O6 octahedra. The corner-sharing octahedral tilt angles are 81°. Bi(1) is bonded to one O(3), one O(4), one O(5), one O(6), and two equivalent O(2) atoms to form distorted BiO6 octahedra that share  a cornercorner with one K(3)O6 octahedra, corners with two equivalent As(2)O4 tetrahedra, corners with four equivalent As(1)O4 tetrahedra, and  an edgeedge with one Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles are 81°. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form AsO4 tetrahedra that share corners with two equivalent K(3)O6 octahedra and corners with four equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 19-66°. In the second As site, As(2) is bonded to two equivalent O(3) and two equivalent O(5) atoms to form AsO4 tetrahedra that share corners with two equivalent K(3)O6 octahedra and corners with four equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-60°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one K(2), two equivalent K(3), and one As(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Bi(1) and one As(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one K(2), one K(3), one Bi(1), and one As(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Bi(1), and one As(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Bi(1), and one As(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to two equivalent K(1), one Bi(1), and one As(1) atom. is represented by the CIF card [CIF]
data_K3Bi2(AsO4)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.998
_cell_length_b   9.998
_cell_length_c   7.177
_cell_angle_alpha   72.683
_cell_angle_beta   72.683
_cell_angle_gamma   89.284
_symmetry_Int_Tables_number   1
_cell_volume   651.653
_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
  K  K0  1  0.986  0.014  0.250  1.0
  K  K1  1  0.276  0.724  0.750  1.0
  K  K2  1  0.724  0.276  0.250  1.0
  K  K3  1  0.500  0.500  0.000  1.0
  K  K4  1  0.014  0.986  0.750  1.0
  K  K5  1  0.500  0.500  0.500  1.0
  Bi  Bi6  1  0.616  0.912  0.166  1.0
  Bi  Bi7  1  0.912  0.616  0.666  1.0
  Bi  Bi8  1  0.088  0.384  0.334  1.0
  Bi  Bi9  1  0.384  0.088  0.834  1.0
  As  As10  1  0.861  0.650  0.139  1.0
  As  As11  1  0.139  0.350  0.861  1.0
  As  As12  1  0.246  0.754  0.250  1.0
  As  As13  1  0.350  0.139  0.361  1.0
  As  As14  1  0.650  0.861  0.639  1.0
  As  As15  1  0.754  0.246  0.750  1.0
  O  O16  1  0.425  0.291  0.361  1.0
  O  O17  1  0.548  0.916  0.844  1.0
  O  O18  1  0.452  0.084  0.156  1.0
  O  O19  1  0.392  0.758  0.327  1.0
  O  O20  1  0.575  0.709  0.639  1.0
  O  O21  1  0.916  0.548  0.344  1.0
  O  O22  1  0.663  0.992  0.409  1.0
  O  O23  1  0.992  0.663  0.909  1.0
  O  O24  1  0.765  0.101  0.952  1.0
  O  O25  1  0.157  0.184  0.838  1.0
  O  O26  1  0.242  0.608  0.173  1.0
  O  O27  1  0.101  0.765  0.452  1.0
  O  O28  1  0.843  0.816  0.162  1.0
  O  O29  1  0.816  0.843  0.662  1.0
  O  O30  1  0.291  0.425  0.861  1.0
  O  O31  1  0.008  0.337  0.091  1.0
  O  O32  1  0.337  0.008  0.591  1.0
  O  O33  1  0.084  0.452  0.656  1.0
  O  O34  1  0.758  0.392  0.827  1.0
  O  O35  1  0.899  0.235  0.548  1.0
  O  O36  1  0.235  0.899  0.048  1.0
  O  O37  1  0.608  0.242  0.673  1.0
  O  O38  1  0.184  0.157  0.338  1.0
  O  O39  1  0.709  0.575  0.139  1.0
[/CIF]
.