ZnSnAsO5 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(3), one O(6), one O(8), and one O(9) atom to form distorted ZnO4 trigonal pyramids that share  a cornercorner with one As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra,  an edgeedge with one Sn(1)O6 octahedra, and  an edgeedge with one Sn(2)O6 octahedra. In the second Zn site, Zn(2) is bonded in a distorted see-saw-like geometry to one O(10), one O(4), one O(5), and one O(7) atom. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(1), one O(10), one O(2), one O(6), one O(7), and one O(9) atom to form SnO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, edges with two equivalent Sn(2)O6 octahedra, and  an edgeedge with one Zn(1)O4 trigonal pyramid. In the second Sn site, Sn(2) is bonded to one O(1), one O(10), one O(2), one O(5), one O(8), and one O(9) atom to form distorted SnO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, edges with two equivalent Sn(1)O6 octahedra, and  an edgeedge with one Zn(1)O4 trigonal pyramid. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form AsO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra, corners with two equivalent Sn(2)O6 octahedra, and  a cornercorner with one Zn(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 43-58°. In the second As site, As(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form AsO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra, corners with two equivalent Sn(2)O6 octahedra, and corners with two equivalent Zn(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 43-61°. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Sn(1), one Sn(2), and one As(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sn(1), one Sn(2), and one As(2) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Zn(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Zn(2) and one As(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Zn(2), one Sn(2), and one As(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Zn(1), one Sn(1), and one As(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Zn(2), one Sn(1), and one As(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Zn(1), one Sn(2), and one As(2) atom. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one Zn(1), one Sn(1), and one Sn(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Zn(2), one Sn(1), and one Sn(2) atom.
ZnSnAsO5 crystallizes in the monoclinic P2_1 space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(3), one O(6), one O(8), and one O(9) atom to form distorted ZnO4 trigonal pyramids that share  a cornercorner with one As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra,  an edgeedge with one Sn(1)O6 octahedra, and  an edgeedge with one Sn(2)O6 octahedra. The Zn(1)-O(3) bond length is 1.91 Å. The Zn(1)-O(6) bond length is 2.19 Å. The Zn(1)-O(8) bond length is 2.15 Å. The Zn(1)-O(9) bond length is 2.00 Å. In the second Zn site, Zn(2) is bonded in a distorted see-saw-like geometry to one O(10), one O(4), one O(5), and one O(7) atom. The Zn(2)-O(10) bond length is 1.95 Å. The Zn(2)-O(4) bond length is 1.90 Å. The Zn(2)-O(5) bond length is 2.16 Å. The Zn(2)-O(7) bond length is 2.25 Å. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(1), one O(10), one O(2), one O(6), one O(7), and one O(9) atom to form SnO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, edges with two equivalent Sn(2)O6 octahedra, and  an edgeedge with one Zn(1)O4 trigonal pyramid. The Sn(1)-O(1) bond length is 2.14 Å. The Sn(1)-O(10) bond length is 2.02 Å. The Sn(1)-O(2) bond length is 2.19 Å. The Sn(1)-O(6) bond length is 2.21 Å. The Sn(1)-O(7) bond length is 2.20 Å. The Sn(1)-O(9) bond length is 2.01 Å. In the second Sn site, Sn(2) is bonded to one O(1), one O(10), one O(2), one O(5), one O(8), and one O(9) atom to form distorted SnO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, edges with two equivalent Sn(1)O6 octahedra, and  an edgeedge with one Zn(1)O4 trigonal pyramid. The Sn(2)-O(1) bond length is 2.57 Å. The Sn(2)-O(10) bond length is 2.47 Å. The Sn(2)-O(2) bond length is 2.45 Å. The Sn(2)-O(5) bond length is 2.43 Å. The Sn(2)-O(8) bond length is 2.42 Å. The Sn(2)-O(9) bond length is 2.27 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form AsO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra, corners with two equivalent Sn(2)O6 octahedra, and  a cornercorner with one Zn(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 43-58°. The As(1)-O(1) bond length is 1.74 Å. The As(1)-O(3) bond length is 1.70 Å. The As(1)-O(5) bond length is 1.73 Å. The As(1)-O(7) bond length is 1.75 Å. In the second As site, As(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form AsO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra, corners with two equivalent Sn(2)O6 octahedra, and corners with two equivalent Zn(1)O4 trigonal pyramids. The corner-sharing octahedral tilt angles range from 43-61°. The As(2)-O(2) bond length is 1.75 Å. The As(2)-O(4) bond length is 1.71 Å. The As(2)-O(6) bond length is 1.75 Å. The As(2)-O(8) bond length is 1.72 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Sn(1), one Sn(2), and one As(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sn(1), one Sn(2), and one As(2) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Zn(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Zn(2) and one As(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Zn(2), one Sn(2), and one As(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Zn(1), one Sn(1), and one As(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Zn(2), one Sn(1), and one As(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Zn(1), one Sn(2), and one As(2) atom. In the ninth O site, O(9) is bonded in a trigonal non-coplanar geometry to one Zn(1), one Sn(1), and one Sn(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Zn(2), one Sn(1), and one Sn(2) atom.