van der Waals corrected density functional calculations of the adsorption of benzene on the Cu (111) surface

摘要: We investigate the performance of several van der Waals (vdW) functionals at calculating interactions between benzene and copper (111) surface, using local orbital approach in SIESTA code. demonstrate importance surface optimized basis sets to calculate properties pure surfaces, including energies work function. quantify errors created (3 × 3) supercells study adsorbate much larger supercells, show non-negligible binding separation distances. examine eight high-symmetry orientations on Cu reporting energies, distance, change The vdW-DF(optB88-vdW) functional provides superior results vdW-DF(revPBE) vdW-DF2(rPW86) functionals, closely matches experimental experimentally deduced values. This demonstrates that methods appropriate combined with a vdW can model adsorption metal surfaces organic molecules.