Cs6U5(AsO7)4 crystallizes in the triclinic P-1 space group. There are three inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(13), one O(6), one O(8), and two equivalent O(5) atoms. In the second Cs site, Cs(2) is bonded in a 7-coordinate geometry to one O(11), one O(12), one O(2), one O(5), one O(9), and two equivalent O(1) atoms. In the third Cs site, Cs(3) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(12), one O(13), and one O(9) atom. There are three inequivalent U sites. In the first U site, U(1) is bonded in a 7-coordinate geometry to one O(10), one O(14), one O(4), one O(7), one O(9), and two equivalent O(3) atoms. In the second U site, U(2) is bonded to one O(11), one O(12), one O(14), one O(2), one O(4), one O(6), and one O(8) atom to form distorted UO7 pentagonal bipyramids that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and  an edgeedge with one U(3)O6 octahedra. In the third U site, U(3) is bonded to two equivalent O(13), two equivalent O(14), and two equivalent O(8) atoms to form distorted UO6 octahedra that share corners with two equivalent As(2)O4 tetrahedra and edges with two equivalent U(2)O7 pentagonal bipyramids. 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 two equivalent U(2)O7 pentagonal bipyramids. 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 U(3)O6 octahedra and corners with two equivalent U(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 59°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Cs(3), two equivalent Cs(2), and one As(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Cs(2), one U(2), and one As(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent U(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one U(1), one U(2), and one As(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Cs(2), two equivalent Cs(1), and one As(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Cs(1), one U(2), and one As(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one U(1) and one As(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Cs(1), one U(2), one U(3), and one As(2) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one Cs(2), one Cs(3), and one U(1) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one Cs(1), one Cs(3), and one U(1) atom. In the eleventh O site, O(11) is bonded in a single-bond geometry to one Cs(1), one Cs(2), and one U(2) atom. In the twelfth O site, O(12) is bonded in a single-bond geometry to one Cs(2), one Cs(3), and one U(2) atom. In the thirteenth O site, O(13) is bonded in a distorted single-bond geometry to one Cs(1), one Cs(3), and one U(3) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one U(1), one U(2), and one U(3) atom.
Cs6U5(AsO7)4 crystallizes in the triclinic P-1 space group. There are three inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(13), one O(6), one O(8), and two equivalent O(5) atoms. The Cs(1)-O(10) bond length is 3.27 Å. The Cs(1)-O(11) bond length is 3.37 Å. The Cs(1)-O(13) bond length is 3.22 Å. The Cs(1)-O(6) bond length is 3.16 Å. The Cs(1)-O(8) bond length is 3.42 Å. There is one shorter (3.05 Å) and one longer (3.08 Å) Cs(1)-O(5) bond length. In the second Cs site, Cs(2) is bonded in a 7-coordinate geometry to one O(11), one O(12), one O(2), one O(5), one O(9), and two equivalent O(1) atoms. The Cs(2)-O(11) bond length is 3.60 Å. The Cs(2)-O(12) bond length is 3.39 Å. The Cs(2)-O(2) bond length is 3.25 Å. The Cs(2)-O(5) bond length is 3.21 Å. The Cs(2)-O(9) bond length is 3.27 Å. There is one shorter (3.05 Å) and one longer (3.11 Å) Cs(2)-O(1) bond length. In the third Cs site, Cs(3) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(12), one O(13), and one O(9) atom. The Cs(3)-O(1) bond length is 3.03 Å. The Cs(3)-O(10) bond length is 3.08 Å. The Cs(3)-O(12) bond length is 3.19 Å. The Cs(3)-O(13) bond length is 3.09 Å. The Cs(3)-O(9) bond length is 3.03 Å. There are three inequivalent U sites. In the first U site, U(1) is bonded in a 7-coordinate geometry to one O(10), one O(14), one O(4), one O(7), one O(9), and two equivalent O(3) atoms. The U(1)-O(10) bond length is 1.84 Å. The U(1)-O(14) bond length is 2.30 Å. The U(1)-O(4) bond length is 2.44 Å. The U(1)-O(7) bond length is 2.24 Å. The U(1)-O(9) bond length is 1.84 Å. There is one shorter (2.35 Å) and one longer (2.58 Å) U(1)-O(3) bond length. In the second U site, U(2) is bonded to one O(11), one O(12), one O(14), one O(2), one O(4), one O(6), and one O(8) atom to form distorted UO7 pentagonal bipyramids that share corners with two equivalent As(1)O4 tetrahedra, corners with two equivalent As(2)O4 tetrahedra, and  an edgeedge with one U(3)O6 octahedra. The U(2)-O(11) bond length is 1.83 Å. The U(2)-O(12) bond length is 1.84 Å. The U(2)-O(14) bond length is 2.38 Å. The U(2)-O(2) bond length is 2.34 Å. The U(2)-O(4) bond length is 2.39 Å. The U(2)-O(6) bond length is 2.31 Å. The U(2)-O(8) bond length is 2.51 Å. In the third U site, U(3) is bonded to two equivalent O(13), two equivalent O(14), and two equivalent O(8) atoms to form distorted UO6 octahedra that share corners with two equivalent As(2)O4 tetrahedra and edges with two equivalent U(2)O7 pentagonal bipyramids. Both U(3)-O(13) bond lengths are 1.85 Å. Both U(3)-O(14) bond lengths are 2.21 Å. Both U(3)-O(8) bond lengths are 2.41 Å. 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 two equivalent U(2)O7 pentagonal bipyramids. The As(1)-O(1) bond length is 1.68 Å. The As(1)-O(2) bond length is 1.71 Å. The As(1)-O(3) bond length is 1.75 Å. The As(1)-O(4) bond length is 1.76 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 U(3)O6 octahedra and corners with two equivalent U(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 59°. The As(2)-O(5) bond length is 1.68 Å. The As(2)-O(6) bond length is 1.73 Å. The As(2)-O(7) bond length is 1.74 Å. The As(2)-O(8) bond length is 1.76 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Cs(3), two equivalent Cs(2), and one As(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Cs(2), one U(2), and one As(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent U(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one U(1), one U(2), and one As(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Cs(2), two equivalent Cs(1), and one As(2) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Cs(1), one U(2), and one As(2) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one U(1) and one As(2) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Cs(1), one U(2), one U(3), and one As(2) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one Cs(2), one Cs(3), and one U(1) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one Cs(1), one Cs(3), and one U(1) atom. In the eleventh O site, O(11) is bonded in a single-bond geometry to one Cs(1), one Cs(2), and one U(2) atom. In the twelfth O site, O(12) is bonded in a single-bond geometry to one Cs(2), one Cs(3), and one U(2) atom. In the thirteenth O site, O(13) is bonded in a distorted single-bond geometry to one Cs(1), one Cs(3), and one U(3) atom. In the fourteenth O site, O(14) is bonded in a distorted trigonal planar geometry to one U(1), one U(2), and one U(3) atom.