Lowest-energy structures of (WO3)n (2 ≤ n ≤ 12) clusters from first-principles global search

► Lowest-energy structures of (WO3)n clusters (n = 2-12) determined by genetic algorithm combined by DFT method. ► W-O alternating cage configurations found for larger clusters with n ≥ 8 and resemble the crystalline bulk structures. ► The occupied states originate from oxygen-2p electrons and the unoccupied states from tungsten-5d electrons.