Structure of NO dimer monolayer on Rh(1Â 1Â 1)

► In the (NO)2/Rh(1 1 1) system, the monolayer other than the monomer was calculated. ► The structure is stable if the NO dimer on the Rh surface forms the monolayer. ► The structures of NO dimer, the monolayer and (NO)2/Rh(1 1 1) have been proposed. ► There are five possible structures for NO dimer monolayer on Rh(1 1 1).