DYNAMICS OF DISSOCIATIVE CHEMISORPTION - CL2 SI(111)-(2X1)/

We report the first simulation of a surface chemical reaction performe d with the ab initio molecular dynamics approach. A set of trajectorie s with different initial conditions has been generated for single Cl2 molecules impinging on the Si(111)-2 x 1 surface with incident transla tional energy of 1 eV. We observe a high probability of dissociation, triggered by active sites on the pi-bonded chains, and accompanied by a large surface response and local rehybridization effects.