Comparative Theoretical Study of H₂ Eley–Rideal Recombination Dynamics on W(100) and W(110)

Quasiclassical molecular dynamics simulations are performed to study the Eley–Rideal recombination of H 2 on two crystallographic planes of tungsten. Potential energy surfaces, based on density functional theory, are used to describe the H+H/W(100, 110) interactions. The calculations are carried out within the single adsorbate limit under normal incidence of the impinging H atoms. The influence of the crystallographic anisotropy on reaction cross sections and energy distribution of the formed molecules is analyzed in detail. Despite some discrepancies in the dynamics of recombination between W(100) and W(110) surfaces, translational, rotational, and vibrational energies of the formed molecules do not depend significantly on surface symmetry. Vibrational distribution of formed H 2 molecules are found in good agreement with experiments.