The material described by Ca3W3As4O16 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and two equivalent O(1) atoms. In the second Ca site, Ca(2) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(8) atoms to form distorted CaO6 octahedra that share corners with four equivalent As(1)O4 tetrahedra and edges with two equivalent W(1)O5 square pyramids. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(2), one O(4), one O(7), and one O(8) atom to form WO5 square pyramids that share corners with three equivalent As(1)O4 tetrahedra and  an edgeedge with one Ca(2)O6 octahedra. In the second W site, W(2) is bonded in a square co-planar geometry to two equivalent O(5) and two equivalent O(7) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form AsO4 tetrahedra that share corners with two equivalent Ca(2)O6 octahedra and corners with three equivalent W(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 41-60°. In the second As site, As(2) is bonded in a distorted trigonal non-coplanar geometry to one O(2), one O(3), and one O(5) atom. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Ca(1), one W(1), and one W(2) atom. In the second O site, O(8) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one W(1), and one As(1) atom. In the third O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one W(1), and one As(1) atom. In the fourth O site, O(2) is bonded in a trigonal non-coplanar geometry to one Ca(2), one W(1), and one As(2) atom. In the fifth O site, O(3) is bonded in a bent 150 degrees geometry to one Ca(1) and one As(2) atom. In the sixth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one W(1), and one As(1) atom. In the seventh O site, O(5) is bonded in a trigonal non-coplanar geometry to one Ca(1), one W(2), and one As(2) atom. In the eighth O site, O(6) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(2), and one As(1) atom. is represented by the CIF card [CIF]
data_Ca3As4W3O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.215
_cell_length_b   10.505
_cell_length_c   17.604
_cell_angle_alpha   59.221
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   828.543
_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
  Ca  Ca0  1  0.028  0.729  0.268  1.0
  Ca  Ca1  1  0.528  0.271  0.232  1.0
  Ca  Ca2  1  0.972  0.271  0.732  1.0
  Ca  Ca3  1  0.472  0.729  0.768  1.0
  Ca  Ca4  1  0.000  0.000  0.000  1.0
  Ca  Ca5  1  0.500  0.000  0.500  1.0
  As  As6  1  0.511  0.954  0.165  1.0
  As  As7  1  0.887  0.598  0.117  1.0
  As  As8  1  0.387  0.402  0.383  1.0
  As  As9  1  0.613  0.598  0.617  1.0
  As  As10  1  0.489  0.046  0.835  1.0
  As  As11  1  0.113  0.402  0.883  1.0
  As  As12  1  0.989  0.954  0.665  1.0
  As  As13  1  0.011  0.046  0.335  1.0
  W  W14  1  0.957  0.788  0.897  1.0
  W  W15  1  0.043  0.212  0.103  1.0
  W  W16  1  0.457  0.212  0.603  1.0
  W  W17  1  0.543  0.788  0.397  1.0
  W  W18  1  0.500  0.500  0.000  1.0
  W  W19  1  0.000  0.500  0.500  1.0
  O  O20  1  0.987  0.200  0.227  1.0
  O  O21  1  0.353  0.221  0.491  1.0
  O  O22  1  0.822  0.667  0.185  1.0
  O  O23  1  0.880  0.899  0.328  1.0
  O  O24  1  0.178  0.333  0.815  1.0
  O  O25  1  0.513  0.200  0.727  1.0
  O  O26  1  0.322  0.333  0.315  1.0
  O  O27  1  0.925  0.516  0.611  1.0
  O  O28  1  0.174  0.903  0.606  1.0
  O  O29  1  0.013  0.800  0.773  1.0
  O  O30  1  0.620  0.899  0.828  1.0
  O  O31  1  0.075  0.484  0.389  1.0
  O  O32  1  0.728  0.322  0.057  1.0
  O  O33  1  0.826  0.097  0.394  1.0
  O  O34  1  0.170  0.002  0.866  1.0
  O  O35  1  0.670  0.998  0.634  1.0
  O  O36  1  0.228  0.678  0.443  1.0
  O  O37  1  0.678  0.667  0.685  1.0
  O  O38  1  0.674  0.097  0.894  1.0
  O  O39  1  0.425  0.484  0.889  1.0
  O  O40  1  0.330  0.002  0.366  1.0
  O  O41  1  0.830  0.998  0.134  1.0
  O  O42  1  0.647  0.779  0.509  1.0
  O  O43  1  0.853  0.779  0.009  1.0
  O  O44  1  0.272  0.678  0.943  1.0
  O  O45  1  0.487  0.800  0.273  1.0
  O  O46  1  0.120  0.101  0.672  1.0
  O  O47  1  0.326  0.903  0.106  1.0
  O  O48  1  0.147  0.221  0.991  1.0
  O  O49  1  0.575  0.516  0.111  1.0
  O  O50  1  0.772  0.322  0.557  1.0
  O  O51  1  0.380  0.101  0.172  1.0
[/CIF]
.
The material described by Ca3W3As4O16 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 8-coordinate geometry to one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and two equivalent O(1) atoms. In the second Ca site, Ca(2) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(8) atoms to form distorted CaO6 octahedra that share corners with four equivalent As(1)O4 tetrahedra and edges with two equivalent W(1)O5 square pyramids. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(2), one O(4), one O(7), and one O(8) atom to form WO5 square pyramids that share corners with three equivalent As(1)O4 tetrahedra and  an edgeedge with one Ca(2)O6 octahedra. In the second W site, W(2) is bonded in a square co-planar geometry to two equivalent O(5) and two equivalent O(7) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(4), one O(6), and one O(8) atom to form AsO4 tetrahedra that share corners with two equivalent Ca(2)O6 octahedra and corners with three equivalent W(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 41-60°. In the second As site, As(2) is bonded in a distorted trigonal non-coplanar geometry to one O(2), one O(3), and one O(5) atom. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Ca(1), one W(1), and one W(2) atom. In the second O site, O(8) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one W(1), and one As(1) atom. In the third O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one W(1), and one As(1) atom. In the fourth O site, O(2) is bonded in a trigonal non-coplanar geometry to one Ca(2), one W(1), and one As(2) atom. In the fifth O site, O(3) is bonded in a bent 150 degrees geometry to one Ca(1) and one As(2) atom. In the sixth O site, O(4) is bonded in a 3-coordinate geometry to one Ca(1), one W(1), and one As(1) atom. In the seventh O site, O(5) is bonded in a trigonal non-coplanar geometry to one Ca(1), one W(2), and one As(2) atom. In the eighth O site, O(6) is bonded in a 2-coordinate geometry to one Ca(1), one Ca(2), and one As(1) atom. is represented by the CIF card [CIF]
data_Ca3As4W3O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.215
_cell_length_b   10.505
_cell_length_c   17.604
_cell_angle_alpha   59.221
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   828.543
_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
  Ca  Ca0  1  0.028  0.729  0.268  1.0
  Ca  Ca1  1  0.528  0.271  0.232  1.0
  Ca  Ca2  1  0.972  0.271  0.732  1.0
  Ca  Ca3  1  0.472  0.729  0.768  1.0
  Ca  Ca4  1  0.000  0.000  0.000  1.0
  Ca  Ca5  1  0.500  0.000  0.500  1.0
  As  As6  1  0.511  0.954  0.165  1.0
  As  As7  1  0.887  0.598  0.117  1.0
  As  As8  1  0.387  0.402  0.383  1.0
  As  As9  1  0.613  0.598  0.617  1.0
  As  As10  1  0.489  0.046  0.835  1.0
  As  As11  1  0.113  0.402  0.883  1.0
  As  As12  1  0.989  0.954  0.665  1.0
  As  As13  1  0.011  0.046  0.335  1.0
  W  W14  1  0.957  0.788  0.897  1.0
  W  W15  1  0.043  0.212  0.103  1.0
  W  W16  1  0.457  0.212  0.603  1.0
  W  W17  1  0.543  0.788  0.397  1.0
  W  W18  1  0.500  0.500  0.000  1.0
  W  W19  1  0.000  0.500  0.500  1.0
  O  O20  1  0.987  0.200  0.227  1.0
  O  O21  1  0.353  0.221  0.491  1.0
  O  O22  1  0.822  0.667  0.185  1.0
  O  O23  1  0.880  0.899  0.328  1.0
  O  O24  1  0.178  0.333  0.815  1.0
  O  O25  1  0.513  0.200  0.727  1.0
  O  O26  1  0.322  0.333  0.315  1.0
  O  O27  1  0.925  0.516  0.611  1.0
  O  O28  1  0.174  0.903  0.606  1.0
  O  O29  1  0.013  0.800  0.773  1.0
  O  O30  1  0.620  0.899  0.828  1.0
  O  O31  1  0.075  0.484  0.389  1.0
  O  O32  1  0.728  0.322  0.057  1.0
  O  O33  1  0.826  0.097  0.394  1.0
  O  O34  1  0.170  0.002  0.866  1.0
  O  O35  1  0.670  0.998  0.634  1.0
  O  O36  1  0.228  0.678  0.443  1.0
  O  O37  1  0.678  0.667  0.685  1.0
  O  O38  1  0.674  0.097  0.894  1.0
  O  O39  1  0.425  0.484  0.889  1.0
  O  O40  1  0.330  0.002  0.366  1.0
  O  O41  1  0.830  0.998  0.134  1.0
  O  O42  1  0.647  0.779  0.509  1.0
  O  O43  1  0.853  0.779  0.009  1.0
  O  O44  1  0.272  0.678  0.943  1.0
  O  O45  1  0.487  0.800  0.273  1.0
  O  O46  1  0.120  0.101  0.672  1.0
  O  O47  1  0.326  0.903  0.106  1.0
  O  O48  1  0.147  0.221  0.991  1.0
  O  O49  1  0.575  0.516  0.111  1.0
  O  O50  1  0.772  0.322  0.557  1.0
  O  O51  1  0.380  0.101  0.172  1.0
[/CIF]
.