RbUAsO9 crystallizes in the monoclinic P2/c space group. Rb(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(3), one O(4), one O(5), one O(7), and two equivalent O(11) atoms. There are two inequivalent U sites. In the first U site, U(1) is bonded to one O(3), one O(6), two equivalent O(8), and two equivalent O(9) atoms to form UO6 octahedra that share corners with four equivalent As(1)O4 tetrahedra. In the second U site, U(2) is bonded to one O(10), one O(7), two equivalent O(1), and two equivalent O(2) atoms to form UO6 octahedra that share corners with four equivalent As(2)O4 tetrahedra. There are two inequivalent As sites. In the first As site, As(1) is bonded to two equivalent O(8) and two equivalent O(9) atoms to form AsO4 tetrahedra that share corners with four equivalent U(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-38°. In the second As site, As(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form AsO4 tetrahedra that share corners with four equivalent U(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-43°. There are eleven inequivalent O sites. In the first O site, O(7) is bonded in a single-bond geometry to two equivalent Rb(1) and one U(2) atom. In the second O site, O(8) is bonded in a bent 150 degrees geometry to one U(1) and one As(1) atom. In the third O site, O(9) is bonded in a bent 150 degrees geometry to one U(1) and one As(1) atom. In the fourth O site, O(10) is bonded in a single-bond geometry to two equivalent Rb(1) and one U(2) atom. In the fifth O site, O(1) is bonded in a 3-coordinate geometry to one Rb(1), one U(2), and one As(2) atom. In the sixth O site, O(11) is bonded in an L-shaped geometry to two equivalent Rb(1) atoms. In the seventh O site, O(2) is bonded in a distorted bent 150 degrees geometry to one U(2) and one As(2) atom. In the eighth O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one U(1) atom. In the ninth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Rb(1) and one O(5) atom. In the tenth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Rb(1) and one O(4) atom. In the eleventh O site, O(6) is bonded in a single-bond geometry to one U(1) atom.
RbUAsO9 crystallizes in the monoclinic P2/c space group. Rb(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(3), one O(4), one O(5), one O(7), and two equivalent O(11) atoms. The Rb(1)-O(1) bond length is 2.97 Å. The Rb(1)-O(10) bond length is 3.14 Å. The Rb(1)-O(3) bond length is 2.90 Å. The Rb(1)-O(4) bond length is 3.40 Å. The Rb(1)-O(5) bond length is 3.26 Å. The Rb(1)-O(7) bond length is 3.32 Å. There is one shorter (2.86 Å) and one longer (3.10 Å) Rb(1)-O(11) bond length. There are two inequivalent U sites. In the first U site, U(1) is bonded to one O(3), one O(6), two equivalent O(8), and two equivalent O(9) atoms to form UO6 octahedra that share corners with four equivalent As(1)O4 tetrahedra. The U(1)-O(3) bond length is 1.89 Å. The U(1)-O(6) bond length is 1.81 Å. Both U(1)-O(8) bond lengths are 2.24 Å. Both U(1)-O(9) bond lengths are 2.28 Å. In the second U site, U(2) is bonded to one O(10), one O(7), two equivalent O(1), and two equivalent O(2) atoms to form UO6 octahedra that share corners with four equivalent As(2)O4 tetrahedra. The U(2)-O(10) bond length is 1.83 Å. The U(2)-O(7) bond length is 1.85 Å. Both U(2)-O(1) bond lengths are 2.27 Å. Both U(2)-O(2) bond lengths are 2.28 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded to two equivalent O(8) and two equivalent O(9) atoms to form AsO4 tetrahedra that share corners with four equivalent U(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-38°. Both As(1)-O(8) bond lengths are 1.72 Å. Both As(1)-O(9) bond lengths are 1.72 Å. In the second As site, As(2) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form AsO4 tetrahedra that share corners with four equivalent U(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-43°. Both As(2)-O(1) bond lengths are 1.72 Å. Both As(2)-O(2) bond lengths are 1.71 Å. There are eleven inequivalent O sites. In the first O site, O(7) is bonded in a single-bond geometry to two equivalent Rb(1) and one U(2) atom. In the second O site, O(8) is bonded in a bent 150 degrees geometry to one U(1) and one As(1) atom. In the third O site, O(9) is bonded in a bent 150 degrees geometry to one U(1) and one As(1) atom. In the fourth O site, O(10) is bonded in a single-bond geometry to two equivalent Rb(1) and one U(2) atom. In the fifth O site, O(1) is bonded in a 3-coordinate geometry to one Rb(1), one U(2), and one As(2) atom. In the sixth O site, O(11) is bonded in an L-shaped geometry to two equivalent Rb(1) atoms. In the seventh O site, O(2) is bonded in a distorted bent 150 degrees geometry to one U(2) and one As(2) atom. In the eighth O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one U(1) atom. In the ninth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Rb(1) and one O(5) atom. The O(4)-O(5) bond length is 1.23 Å. In the tenth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Rb(1) and one O(4) atom. In the eleventh O site, O(6) is bonded in a single-bond geometry to one U(1) atom.