Regensburg 2019 – scientific programme
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DS: Fachverband Dünne Schichten
DS 18: Frontiers of Electronic-Structure Theory: Focus on the Interface Challenge VI (joint session O/CPP/DS/TT)
DS 18.6: Talk
Wednesday, April 3, 2019, 16:15–16:30, H9
Charge localization at a weakly coupled molecule-metal system studied by linear expansion Δ-self-consistent field density-functional theory (ΔSCF-DFT) — •Hadi H. Arefi1,2, Daniel Corken3, Reinhard Maurer3, F. Stefan Tautz1,2, and Christian Wagner1,2 — 1Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, Germany — 2JARA-Fundamentals of Future Information Technology — 3Department of Chemistry, University of Warwick, Coventry, United Kingdom
Predicting the charge arrangements at the interface between molecules and metals represents a formidable challenge for semi-local approximations to Density Functional Theory (DFT). This could become even more critical when molecules are only weakly coupled to the metal. Single-molecular devices based on such weak coupling have recently been created by molecular manipulation with a scanning probe microscope (SPM), where a single PTCDA (perylene-tetracarboxylic dianhydride) molecule was placed in a free-standing upright configuration either on a SPM tip [1] or on a pedestal of two adatoms on the Ag(111) surface [2]. There are indications that the mechanism stabilizing these unexpected configurations is linked to an integer charge transfer creating a singly occupied molecular orbital. We use the ΔSCF-DFT method [3] to confine charge on the LUMO of the PTCDA and study the consequences with vdW-corrected DFT.
[1] C. Wagner et al. Phys. Rev. Lett. 115, 026101 (2015) [2] T. Esat et al. Nature 558, 573 (2018) [3] R. J Maurer, K. Reuter, JCP 139, 014708 (2013)