Quantification of finite-temperature effects on adsorption geometries of π-conjugated molecules: Azobenzene/Ag(111)
G. Mercurio, R. J. Maurer, W. Liu, S. Hagen, F. Leyssner, P. Tegeder, J. Meyer, A. Tkatchenko, S. Soubatch, K. Reuter, F. S. Tautz, Phys. Rev. B 88, 035421 (2013)
"We obtain the adsorption structure of Azobenzene on Ag(111) with simulation and experiment by accounting for anharmonic temperature effects"
The adsorption structure of the molecular switch azobenzene on Ag(111) is investigated by a combination of normal incidence x-ray standing waves and dispersion-corrected density functional theory. The inclusion of nonlocal collective substrate response (screening) in the dispersion correction improves the description of dense monolayers of azobenzene, which exhibit a substantial torsion of the molecule. Nevertheless, for a quantitative agreement with experiment explicit consideration of the effect of vibrational mode anharmonicity on the adsorption geometry is crucial.