Towards an accurate description of the electronic properties of the biphenylthiol/gold interface: the role of exact exchange.
We investigate the role of the exact exchange in describing the biphenylthiol/gold interface. The study is performed by simulating the electronic properties of mercaptobiphenylthiol and aminobiphenylthiol molecules adsorbed on a Au(23) cluster, using local, semilocal and hybrid functionals and an effective exact exchange method, namely, the localized Hartree-Fock (LHF). We find that the local/semilocal functionals strongly underestimate the charge transfer and the bond dipole at the interface due to the self-interaction-error (SIE), which alters the correct level alignment. On the other hand the LHF method is SIE free and predicts a larger charge transfer and bond dipole. We also found that LHF results can be reproduced using hybrid functionals and that conventional local/semilocal correlation functionals are unable to improve over the exchange-only description.
Fabiano
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National Nanotechnology Laboratory of CNR-INFM, IIT Research Unit, Distretto Tecnologico ISUFI, Via per Arnesano, I-73100 Lecce, Italy.
Piacenza
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D'Agostino
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Della Sala
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