Quantification of finite-temperature effects on adsorption geometries of   $\pi$-conjugated molecules
  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 non-local 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. 
G. Mercurio, R. J. Maurer, W. Liu, S. Hagen, F. Leyssner, P. Tegeder,   J. Meyer, A. Tkatchenko, S. Soubatch, K. Reuter, and...
cond-mat.mtrl-sci cond-mat.mes-hall physics.chem-ph