CaCu4As4(HO13)2 crystallizes in the triclinic P-1 space group. Ca(1) is bonded to two equivalent O(11), two equivalent O(12), and two equivalent O(5) atoms to form distorted CaO6 octahedra that share corners with two equivalent As(2)O4 tetrahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(10), one O(3), one O(7), one O(8), and two equivalent O(2) atoms to form distorted CuO6 octahedra that share corners with two equivalent As(2)O4 tetrahedra, corners with three equivalent As(1)O4 tetrahedra, and  an edgeedge with one Cu(1)O6 octahedra. In the second Cu site, Cu(2) is bonded in a 5-coordinate geometry to one O(3), one O(7), one O(9), and two equivalent O(6) atoms. There are two 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 Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-55°. In the second As site, As(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra and corners with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-58°. H(1) is bonded in a distorted linear geometry to one O(4) and one O(8) atom. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one As(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to two equivalent Cu(1) and one As(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one As(1) atom. In the fourth O site, O(4) is bonded in a distorted water-like geometry to one As(1) and one H(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Ca(1) and one As(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to two equivalent Cu(2) and one As(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one As(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Cu(1), one As(2), and one H(1) atom. In the ninth O site, O(9) is bonded in a single-bond geometry to one Cu(2) atom. In the tenth O site, O(10) is bonded in a single-bond geometry to one Cu(1) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Ca(1) and one O(11) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Ca(1) and one O(13) atom. In the thirteenth O site, O(13) is bonded in a single-bond geometry to one O(12) atom.
CaCu4As4(HO13)2 crystallizes in the triclinic P-1 space group. Ca(1) is bonded to two equivalent O(11), two equivalent O(12), and two equivalent O(5) atoms to form distorted CaO6 octahedra that share corners with two equivalent As(2)O4 tetrahedra. Both Ca(1)-O(11) bond lengths are 2.74 Å. Both Ca(1)-O(12) bond lengths are 2.65 Å. Both Ca(1)-O(5) bond lengths are 2.16 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(10), one O(3), one O(7), one O(8), and two equivalent O(2) atoms to form distorted CuO6 octahedra that share corners with two equivalent As(2)O4 tetrahedra, corners with three equivalent As(1)O4 tetrahedra, and  an edgeedge with one Cu(1)O6 octahedra. The Cu(1)-O(10) bond length is 1.83 Å. The Cu(1)-O(3) bond length is 1.97 Å. The Cu(1)-O(7) bond length is 2.26 Å. The Cu(1)-O(8) bond length is 2.12 Å. There is one shorter (2.00 Å) and one longer (2.20 Å) Cu(1)-O(2) bond length. In the second Cu site, Cu(2) is bonded in a 5-coordinate geometry to one O(3), one O(7), one O(9), and two equivalent O(6) atoms. The Cu(2)-O(3) bond length is 2.22 Å. The Cu(2)-O(7) bond length is 1.96 Å. The Cu(2)-O(9) bond length is 1.77 Å. There is one shorter (1.97 Å) and one longer (2.01 Å) Cu(2)-O(6) bond length. There are two 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 Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 53-55°. The As(1)-O(1) bond length is 1.71 Å. The As(1)-O(2) bond length is 1.74 Å. The As(1)-O(3) bond length is 1.72 Å. The As(1)-O(4) bond length is 1.78 Å. In the second As site, As(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra and corners with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-58°. The As(2)-O(5) bond length is 1.69 Å. The As(2)-O(6) bond length is 1.77 Å. The As(2)-O(7) bond length is 1.75 Å. The As(2)-O(8) bond length is 1.73 Å. H(1) is bonded in a distorted linear geometry to one O(4) and one O(8) atom. The H(1)-O(4) bond length is 1.02 Å. The H(1)-O(8) bond length is 1.58 Å. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one As(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to two equivalent Cu(1) and one As(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one As(1) atom. In the fourth O site, O(4) is bonded in a distorted water-like geometry to one As(1) and one H(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Ca(1) and one As(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to two equivalent Cu(2) and one As(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one As(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Cu(1), one As(2), and one H(1) atom. In the ninth O site, O(9) is bonded in a single-bond geometry to one Cu(2) atom. In the tenth O site, O(10) is bonded in a single-bond geometry to one Cu(1) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Ca(1) and one O(11) atom. The O(11)-O(11) bond length is 1.23 Å. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Ca(1) and one O(13) atom. The O(12)-O(13) bond length is 1.23 Å. In the thirteenth O site, O(13) is bonded in a single-bond geometry to one O(12) atom.