Dynamics of the oxygen molecules scattered from graphite (0001) surface and comparison with experimental data

Abstract

A quasiclassical trajectory dynamics study of molecular oxygen colliding over a free of defects and clean graphite (0001) surface has been performed with a recently published density functional theory based flexible periodic London-Eyring-Polanyi-Sato potential energy surface (PES). Although the PES was mainly constructed for describing accurately the recombination of atomic oxygen over an O-preadsorbed surface, here we show that this PES is also reliable to study the scattering of O2 over graphite surface. Thus, several initial conditions have been explored: collision energies (0.2 ≤ Ecol ≤ 1.2 eV), incident angles (0, 45), surface temperatures (100 ≤ Tsurf ≤ 900 K) and some rovibrational O2 levels (v = 0,1,2 and j = 1,17,25). The calculated polar scattering angular distributions are in good agreement with the experimental ones in a wide range of explored conditions. Moreover, the comparison with hyperthermal experimental data, which was unclear in a previous work, has been finally clarified. The effect of O2 (v,j) internal state on the scattering is very small.