Adsorption of Acetonitrile on Si(111)-(7 × 7)

[Image: see text] The adsorption of acetonitrile (CH(3)CN) on Si(111)-(7 × 7) at a room temperature has been investigated using scanning tunneling microscopy (STM) and first-principles calculations. The site-specific information on adsorption enables us to understand the site-by-site and step-by-step adsorption mechanism. From theoretical simulations, the most stable configuration of CH(3)CN on Si(111)-(7 × 7) is found to be a molecularly chemisorbed CH(3)CN with the carbon and nitrogen atoms of CN bonded to the rest atom and adatom on the Si surface, respectively. Some chemisorption-induced features in the STM topographic image are assigned based on the theoretical calculations.