Berlin 2018 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 8: Solid-liquid interfaces: Structure, Spectroscopy I
O 8.9: Vortrag
Montag, 12. März 2018, 12:30–12:45, MA 144
Decisive Role of Nuclear Quantum Effects on Surface Mediated Water Dissociation at Finite Temperature — •Yair Litman1, Davide Donadio2, Michele Ceriotti3, and Mariana Rossi1 — 1Fritz Haber Insitute of the Max Planck Society, Berlin, Germany — 2University of California, Davis — 3EPFL, Switzerland
Water molecules adsorbed on inorganic substrates play an important role in several technological applications.
In the presence of light atoms in adsorbates, nuclear quantum effects (NQE) influence
the structural stability and the dynamical properties of these systems. In this work [1], we explore NQE on the water dissociation of water wires on stepped Pt(221) surfaces.
We note that there are several competing minima, calling for the inclusion of anharmonic effects in simulations at finite temperatures.
We thus perform ab initio path integral molecular dynamics
(PIMD) in order to calculate NQE contributions to free energies and their interplay with the electronic structure,
making use of an acceleration technique that we propose, based on a spatially-localised ring-polymer contraction. We find that the dissociation process is dominated by ZPE,
which can enhance the rate of dissociation by three orders of magnitude and that the inclusion of anharmonicities
increase the nuclear quantum contribution to the dissociation free energy by
20 % compared to harmonic estimates.
Interestingly, we report how the redistribution of electronic density caused by temperature and NQE can
induce work function changes of up to 0.4 eV with respect to static estimates.
[1] Y. Litman et. al. JCP 148, 102320 (2018).