A new strongly-bound chemisorption structure of benzene on Si(100)

► We have studied chemisorption of benzene on Si(100) by STM and ab initio theory. ► We found a new chemisorbed geometry; inter-dimer butterfly, ID-BF (C). ► This new structure was always obtained in association with a C-type defect. ► Ab initio calculations yield a binding energy of 2.4 eV for this structure. ► The structure is the most stable of all chemisorbed states of benzene on Si(100).