Communication: Coalescence of carbon atoms on Cu (111) surface: Emergence of a stable bridging-metal structure motif.

By combining first principles transition state location and molecular dynamics simulation, we unambiguously identify a carbon atom approaching induced bridging-metal structure formation on Cu (111) surface, which strongly modify the carbon atom coalescence dynamics. The emergence of such a new structural motif turns out to be a result of the subtle balance between Cu-C and Cu-Cu interactions. Based on this picture, a simple theoretical model is proposed, which describes a variety of surface chemistries very well.