Rb3BAs2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 5-coordinate geometry to one B(1) and four equivalent As(1) atoms. In the second Rb site, Rb(2) is bonded in a 7-coordinate geometry to two equivalent B(1) and five equivalent As(1) atoms. B(1) is bonded in a 7-coordinate geometry to one Rb(1), four equivalent Rb(2), and two equivalent As(1) atoms. As(1) is bonded in a 1-coordinate geometry to two equivalent Rb(1), five equivalent Rb(2), and one B(1) atom.
Rb3BAs2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 5-coordinate geometry to one B(1) and four equivalent As(1) atoms. The Rb(1)-B(1) bond length is 3.46 Å. There are two shorter (3.61 Å) and two longer (3.66 Å) Rb(1)-As(1) bond lengths. In the second Rb site, Rb(2) is bonded in a 7-coordinate geometry to two equivalent B(1) and five equivalent As(1) atoms. There is one shorter (3.26 Å) and one longer (3.50 Å) Rb(2)-B(1) bond length. There are a spread of Rb(2)-As(1) bond distances ranging from 3.52-3.75 Å. B(1) is bonded in a 7-coordinate geometry to one Rb(1), four equivalent Rb(2), 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 Rb(1), five equivalent Rb(2), and one B(1) atom.