Rb2Zn5Sb4 crystallizes in the orthorhombic Cmcm space group. Rb(1) is bonded in a 6-coordinate geometry to two equivalent Zn(1), two equivalent Sb(1), and two equivalent Sb(2) atoms. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 4-coordinate geometry to two equivalent Rb(1), two equivalent Sb(1), and two equivalent Sb(2) atoms. In the second Zn site, Zn(2) is bonded in a 4-coordinate geometry to two equivalent Sb(1) and two equivalent Sb(2) atoms. In the third Zn site, Zn(3) is bonded in a 4-coordinate geometry to two equivalent Sb(1) and two equivalent Sb(2) atoms. There are two inequivalent Sb sites. In the first Sb site, Sb(2) is bonded in a 7-coordinate geometry to two equivalent Rb(1), one Zn(3), two equivalent Zn(1), and two equivalent Zn(2) atoms. In the second Sb site, Sb(1) is bonded in a 5-coordinate geometry to two equivalent Rb(1), one Zn(3), two equivalent Zn(1), and two equivalent Zn(2) atoms.
Rb2Zn5Sb4 crystallizes in the orthorhombic Cmcm space group. Rb(1) is bonded in a 6-coordinate geometry to two equivalent Zn(1), two equivalent Sb(1), and two equivalent Sb(2) atoms. Both Rb(1)-Zn(1) bond lengths are 3.63 Å. Both Rb(1)-Sb(1) bond lengths are 3.70 Å. Both Rb(1)-Sb(2) bond lengths are 3.71 Å. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 4-coordinate geometry to two equivalent Rb(1), two equivalent Sb(1), and two equivalent Sb(2) atoms. There is one shorter (2.69 Å) and one longer (2.79 Å) Zn(1)-Sb(1) bond length. Both Zn(1)-Sb(2) bond lengths are 2.72 Å. In the second Zn site, Zn(2) is bonded in a 4-coordinate geometry to two equivalent Sb(1) and two equivalent Sb(2) atoms. Both Zn(2)-Sb(1) bond lengths are 2.75 Å. There is one shorter (2.66 Å) and one longer (2.90 Å) Zn(2)-Sb(2) bond length. In the third Zn site, Zn(3) is bonded in a 4-coordinate geometry to two equivalent Sb(1) and two equivalent Sb(2) atoms. Both Zn(3)-Sb(1) bond lengths are 2.72 Å. Both Zn(3)-Sb(2) bond lengths are 2.79 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(2) is bonded in a 7-coordinate geometry to two equivalent Rb(1), one Zn(3), two equivalent Zn(1), and two equivalent Zn(2) atoms. In the second Sb site, Sb(1) is bonded in a 5-coordinate geometry to two equivalent Rb(1), one Zn(3), two equivalent Zn(1), and two equivalent Zn(2) atoms.