SURFACE CORRUGATION IN THE DISSOCIATIVE ADSORPTION OF H-2 ON CU(100)

First-principles calculations of the potential energy surface for H-2 dissociation on the Cu(100) surface are presented. The height of the t ransition state above the surface and energy barrier are mapped over t he surface. A very marked surface corrugation is found. Normal mode fr equencies at the transition state for two extreme dissociation geometr ies suggest that zero point energy contributes little to surface corru gation. The local density approximation predicts a zero minimum barrie r. Gradient corrections greatly increase the barrier height, but have little effect on the surface corrugation.