caa a22 4500 605488290 CHVBK 20210128100454.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00214-015-1666-y doi (NATIONALLICENCE)springer-10.1007/s00214-015-1666-y Effect of van der Waals interactions in the DFT description of self-assembled monolayers of thiols on gold [Elektronische Daten] [José Fajín, Filipe Teixeira, José Gomes, M. Cordeiro] The structure and energetic properties of self-assembled monolayers (SAMs) of alkanethiol derivatives (simple alkanethiols, mercaptoalkanoic acids and aminoalkanethiols with different chain length) adsorbed on the metallic Au(111) surface are investigated through periodic DFT calculations. To sort out the effect of van der Waals (vdW) interactions on the DFT calculations, the results of the standard GGA-PBE functional are compared with those obtained with approaches including the vdW interactions such as those incorporating the Grimme's (GGA-PBE-D2) and the Tkatchenko-Scheffler's (GGA-PBE-TS) schemes, as well as with the optB86b-vdW density functional. The most significant difference between the two sets of results appears for the adsorption energies per thiol molecules: The standard functional predicts energy values 30-40% lower than those obtained when the van der Waals interactions are taken into account. This is certainly due to a better description of the lateral interactions between the chains of the thiols when including the van der Waals effects. Differences are also found between the adsorption energies predicted by density functionals taking into account the vdW corrections, with values increasing in the order GGA-PBE-D2<GGA-PBE-TS<optB86b-vdW. Furthermore, the functionals considering dispersion interactions favor much more tilted orientations of the SAMs over the surface with respect to those found using the standard GGA functional (the SAMs' tilt angles increase from 17°-24° to 37°-46°), being the former in closer agreement with available experimental data. In contrast, the SAMs' precession angle and monolayer thickness are less affected by the type of DFT exchange-correlation functional employed. In the case of low surface coverage, the chains of the thiols adopt more tilted configurations and tend to lay side-down onto the surface. Springer-Verlag Berlin Heidelberg, 2015 Gold (111) surface nationallicence Thiols nationallicence Periodic density functional theory nationallicence van der Waals effects nationallicence Fajín José LAQV@REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, 4169-007, Porto, Portugal aut Teixeira Filipe LAQV@REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, 4169-007, Porto, Portugal aut Gomes José CICECO, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal aut Cordeiro M. LAQV@REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, 4169-007, Porto, Portugal aut Theoretical Chemistry Accounts Springer Berlin Heidelberg 134/5(2015-05-01), 1-13 1432-881X 134:5<1 2015 134 214 https://doi.org/10.1007/s00214-015-1666-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00214-015-1666-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Fajín José LAQV@REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, 4169-007, Porto, Portugal aut NATIONALLICENCE 700 1- Teixeira Filipe LAQV@REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, 4169-007, Porto, Portugal aut NATIONALLICENCE 700 1- Gomes José CICECO, Department of Chemistry, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal aut NATIONALLICENCE 700 1- Cordeiro M. LAQV@REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, 4169-007, Porto, Portugal aut NATIONALLICENCE 773 0- Theoretical Chemistry Accounts Springer Berlin Heidelberg 134/5(2015-05-01), 1-13 1432-881X 134:5<1 2015 134 214