Cs3BAs2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 4-coordinate geometry to two equivalent B(1) and two equivalent As(1) atoms. In the second Cs site, Cs(2) is bonded in a 5-coordinate geometry to one B(1) and four equivalent As(1) atoms. B(1) is bonded in a distorted linear geometry to one Cs(2), four equivalent Cs(1), and two equivalent As(1) atoms. As(1) is bonded in a 1-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), and one B(1) atom.
Cs3BAs2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 4-coordinate geometry to two equivalent B(1) and two equivalent As(1) atoms. There is one shorter (3.44 Å) and one longer (3.63 Å) Cs(1)-B(1) bond length. There is one shorter (3.67 Å) and one longer (3.97 Å) Cs(1)-As(1) bond length. In the second Cs site, Cs(2) is bonded in a 5-coordinate geometry to one B(1) and four equivalent As(1) atoms. The Cs(2)-B(1) bond length is 3.66 Å. All Cs(2)-As(1) bond lengths are 3.82 Å. B(1) is bonded in a distorted linear geometry to one Cs(2), four equivalent Cs(1), and two equivalent As(1) atoms. Both B(1)-As(1) bond lengths are 1.87 Å. As(1) is bonded in a 1-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), and one B(1) atom.