Improved Theoretical\nDescription of the H<sub>2</sub> Chemisorption\nDynamics on the W(100) Surface

The\ndynamics of H<sub>2</sub> chemisorption on W(100) is investigated\nby means of molecular dynamics simulations performed on a new potential\nenergy surface (PES) that includes nonlocal van der Waals interactions.\nThe PES is based on density functional theory (DFT) calculations using\nthe vdW-DF2 functional. The dissociative sticking curve is found to\nbe in very good agreement with experiment for collision energies higher\nthan 150 meV. At lower energies, discrepancies still exist and molecular\ndynamic trapping plays a significant role as suggested by experiments,\nbut quantitative agreement still requires further investigation. The\ndynamics is analyzed in the light of previous results based on the\nPW91 functional.