Formation and diffusion of S-decorated Cu clusters onc Cu(111)

S-decorated Cu trimers are a likely agent of S-enhanced Cu transport between islands on Cu(111). According to nb initio calculations, excellent S bonding to trimer-Cu dangling valence results in an ad-Cu3S3 formation energy of only similar to 0.28 eV, compared to 0.79 eV for a self-adsorbed Cu atom, and a diffusion barrier less than or equal to 0.35 eV.