Rb2Se3 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 7-coordinate geometry to one Se(2) and six equivalent Se(1) atoms. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to two equivalent Se(2) and six equivalent Se(1) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Rb(1), three equivalent Rb(2), and one Se(2) atom to form a mixture of distorted edge, corner, and face-sharing SeRb6Se pentagonal bipyramids. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to one Rb(1), two equivalent Rb(2), and two equivalent Se(1) atoms.
Rb2Se3 crystallizes in the orthorhombic Cmc2_1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 7-coordinate geometry to one Se(2) and six equivalent Se(1) atoms. The Rb(1)-Se(2) bond length is 3.46 Å. There are two shorter (3.55 Å) and four longer (3.59 Å) Rb(1)-Se(1) bond lengths. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to two equivalent Se(2) and six equivalent Se(1) atoms. There is one shorter (3.40 Å) and one longer (3.81 Å) Rb(2)-Se(2) bond length. There are a spread of Rb(2)-Se(1) bond distances ranging from 3.48-3.60 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to three equivalent Rb(1), three equivalent Rb(2), and one Se(2) atom to form a mixture of distorted edge, corner, and face-sharing SeRb6Se pentagonal bipyramids. The Se(1)-Se(2) bond length is 2.39 Å. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to one Rb(1), two equivalent Rb(2), and two equivalent Se(1) atoms.