Adsorption-induced lattice relaxation and diffusion by concerted substitution

Ab initio calculations show that the barrier to surface self-diffusion by c oncerted substitution (CS) is lower on those transition-metal (100) surface s where the substrate relaxation around an adatom, and the corresponding en ergy gain, are greater. Stress calculations contradict the notion that lowe r barrier CS corresponds to larger tensile stress reduction along the CS di ffusion path. [S0163-1829 (99)07007-1].