Fig. 2. Side and top views of [(C₂₀H₁₀^4–)/5Li⁺/(C₂₀H₁₀^4–)]^3– (A) and [(C₂₀H₁₀^3–)/4Cs⁺/(C₂₀H₁₀^3–)]^2– (B) based on their X-ray diffraction studies along with the optimized geometry of the Cs₄-sandwich based on DFT calculations (C, exterior Cs ions are not shown).