Six-dimensional potential energy surfaces of the dissociative chemisorption of HCl on Ag(111) with three density functionals.

We first constructed six-dimensional potential energy surfaces (PESs) for the dissociative chemisorption of HCl on rigid Ag(111). Three global PESs were calculated using the neural network method based on extensive density functional theory (DFT) calculations with Perdew-Burke-Ernzerhof, Perdew-Wang91, and revised Perdew-Burke-Ernzerhof functionals, respectively. The resulting three PESs are all accurately fitted and smooth, based on the small fitting errors and good agreements between the fitted PESs and the direct DFT calculations. Time-dependent wave packet calculations show that the PESs are very well converged with respect to the fitting process, as well as the number of DFT data points. Comparisons of three PESs and time-dependent quantum dynamics results on the three PESs were given and discussed. The validity of site-averaging approximation holds for the title reaction, where the 25 site-averaged four-dimensional dissociation probability can accurately reproduce the six-dimensional dissociation probability on the current three PESs. We expect that the current theoretical investigations can stimulate the experimental work for this gas-surface reaction.