TY  - JOUR
A1  - Füchsel, Gernot
A1  - Tremblay, Jean Christophe
A1  - Klamroth, Tillmann
A1  - Saalfrank, Peter
T1  - Quantum dynamical simulations of the femtosecond-laser-induced ultrafast desorption of H2 and D2 from Ru(0001)
JF  - ChemPhysChem : a European journal of chemical physics and physical chemistry
N2  - We investigate the recombinative desorption of hydrogen and deuterium from a Ru(0001) surface initiated by femtosecond laser pulses. We adopt a quantum mechanical two-state model including three molecular degrees of freedom to describe the dynamics within the desorption induced by electronic transition (DIET) limit. The energy distributions as well as the state-resolved and ensemble properties of the desorbed molecules are analyzed in detail by using the time-energy method. Our results shed light on the experimentally observed 1) large isotopic effects regarding desorption yields and translational energies and 2) the nonequal energy partitioning into internal and translational modes. In particular, it is shown that a single temperature is sufficient to characterize the energy distributions for all degrees of freedom. Further, we confirm that quantization effects play an important role in the determination of the energy partitioning.
KW  - quantum dynamics
KW  - laser chemistry
KW  - isotope effects
KW  - surface chemistry
KW  - ultrafast reactions
Y1  - 2013
U6  - https://doi.org/10.1002/cphc.201200940
SN  - 1439-4235
VL  - 14
IS  - 7
SP  - 1471
EP  - 1478
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Füchsel, Gernot
A1  - Tremblay, Jean Christophe
A1  - Saalfrank, Peter
T1  - A six-dimensional potential energy surface for Ru(0001)(2x2):CO
JF  - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr
N2  - We present a new global ground state potential energy surface (PES) for carbon monoxide at a coverage of 1/4, on a rigid Ru(0001) surface [Ru(0001)(2x2):CO]. All six adsorbate degrees of freedom are considered. For constructing the PES, we make use of more than 90 000 points calculated with periodic density functional theory using the RPBE exchange-correlation functional and an empirical van der Waals correction. These points are used for interpolation, utilizing a symmetry-adapted corrugation reducing procedure (CRP). Three different interpolation schemes with increasing accuracy have been realized, giving rise to three flavours of the CRP PES. The CRP PES yields in agreement with the DFT reference and experiments, the atop position of CO to be the most stable adsorption geometry, for the most accurate interpolation with an adsorption energy of 1.69 eV. The CRP PES shows that diffusion parallel to the surface is hindered by a barrier of 430 meV, and that dissociation is facilitated but still activated. As a first "real" application and further test of the new potential, the six-dimensional vibrational Schrodinger equation is solved variationally to arrive at fully coupled, anharmonic frequencies and vibrational wavefunctions for the vibrating, adsorbed CO molecule. Good agreement with experiment is found also here. Being analytical, the new PES opens an efficient way towards multidimensional dynamics. (C) 2014 AIP Publishing LLC.
Y1  - 2014
U6  - https://doi.org/10.1063/1.4894083
SN  - 0021-9606
SN  - 1089-7690
VL  - 141
IS  - 9
PB  - American Institute of Physics
CY  - Melville
ER  -