Cs2As3 crystallizes in the orthorhombic Fmmm space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 8-coordinate geometry to four equivalent As(1) and four equivalent As(2) atoms. In the second Cs site, Cs(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 Cs(1), four equivalent Cs(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 Cs(2), four equivalent Cs(1), and two equivalent As(1) atoms.
Cs2As3 crystallizes in the orthorhombic Fmmm space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 8-coordinate geometry to four equivalent As(1) and four equivalent As(2) atoms. All Cs(1)-As(1) bond lengths are 3.83 Å. All Cs(1)-As(2) bond lengths are 3.91 Å. In the second Cs site, Cs(2) is bonded in a 10-coordinate geometry to two equivalent As(2) and eight equivalent As(1) atoms. Both Cs(2)-As(2) bond lengths are 3.75 Å. There are four shorter (3.74 Å) and four longer (3.88 Å) Cs(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 Cs(1), four equivalent Cs(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 2.39 Å. In the second As site, As(2) is bonded in a 8-coordinate geometry to two equivalent Cs(2), four equivalent Cs(1), and two equivalent As(1) atoms.