Rb2As3 crystallizes in the orthorhombic Fmmm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to four equivalent As(1) and four equivalent As(2) atoms to form a mixture of edge, face, and corner-sharing RbAs8 hexagonal bipyramids. In the second Rb site, Rb(2) is bonded in a 10-coordinate geometry to two equivalent As(2) and eight equivalent As(1) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to two equivalent Rb(1), four equivalent Rb(2), one As(1), and one As(2) atom. In the second As site, As(2) is bonded in a 8-coordinate geometry to two equivalent Rb(2), four equivalent Rb(1), and two equivalent As(1) atoms.
Rb2As3 crystallizes in the orthorhombic Fmmm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to four equivalent As(1) and four equivalent As(2) atoms to form a mixture of edge, face, and corner-sharing RbAs8 hexagonal bipyramids. All Rb(1)-As(1) bond lengths are 3.67 Å. All Rb(1)-As(2) bond lengths are 3.71 Å. In the second Rb site, Rb(2) is bonded in a 10-coordinate geometry to two equivalent As(2) and eight equivalent As(1) atoms. Both Rb(2)-As(2) bond lengths are 3.60 Å. There are four shorter (3.60 Å) and four longer (3.68 Å) Rb(2)-As(1) bond lengths. There are two inequivalent As sites. In the first As site, As(1) is bonded in a 8-coordinate geometry to two equivalent Rb(1), four equivalent Rb(2), one As(1), and one As(2) atom. The As(1)-As(1) bond length is 2.39 Å. The As(1)-As(2) bond length is 2.40 Å. In the second As site, As(2) is bonded in a 8-coordinate geometry to two equivalent Rb(2), four equivalent Rb(1), and two equivalent As(1) atoms.