Detailed description of the flexible periodic London-Eyring-Polanyi-Sato potential energy function

An extension of the periodic London-Eyring-Polanyi-Sato (PLEPS) function has been recently proposed in order to accurately describe the six-dimensional potential energy surface for two atoms interacting with a periodic rigid surface. However, only the main features were presented so that the present paper aims at precisely describing the necessary details to achieve the fitting procedure of the so-called flexible periodic LEPS function (FPLEPS) to a set of ab initio electronic structure calculations. The topology of the resulting global potential energy surface is compared to that of previously developed models, including a state-of-the-art ab initio potential, for N2 interacting with W(1 0 0). The dynamics of dissociative adsorption using these different models is analyzed.