The adsorption structures of cis-2-butene-1,4-diol (C 4 H 8 O 2 ) on a Si(100) surface were investigated using density functional theory (DFT) calculations. The most stable configuration involves the adsorbed cis-2-butene-1,4-diol molecule with dissociated H forming a bridged structure between two surface Si atoms through dual O–Si bonding. The corresponding simulated images were able to explain previously reported experimental observations. The two stable bridged structures, either on-top or end-bridged, produced STM images consistent with the experimentally identified features.