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Recent years have seen a tremendous progress in the microscopic theoretical treatment of surfaces and processes on surfaces. While some decades ago a phenomenological thermodynamic approach was dominant, a variety of surface properties can now be described from first principles, i.e. without invoking any empirical parameters. Consequently, the field of(More)
The electronic charge density distribution or the electrostatic atomic potential of a solid or molecule contains information not only on the atomic structure, but also on the electronic properties, such as the nature of the chemical bonds or the degree of ionization of atoms. However, the redistribution of charge due to chemical bonding is small compared(More)
Recent theoretical progress in gas-surface reaction dynamics, a field relevant to heterogeneous catalysis, is described. One of the most fundamental reactions, the dissociative chemisorption of H2 on metal surfaces, can now be treated accurately using quantum mechanics. Density functional theory is used to compute the molecule-surface interaction, and the(More)
A recent scanning tunneling microscopy study by Mitsui et al. [Nature (London) 422, 705 (2003)] challenged the well-accepted picture based on early studies of Langmuir that an ensemble of at least two empty, catalytically active sites is required for the dissociative adsorption; instead, aggregates of three or more vacancies should be necessary. We have(More)
A neural network NN approach is proposed for the representation of six-dimensional ab initio potentialenergy surfaces PES for the dissociation of a diatomic molecule at surfaces. We report tests of NN representations that are fitted to six-dimensional analytical PESs for H2 dissociation on the clean and the sulfur covered Pd 100 surfaces. For the present(More)
We report the first six-dimensional quantum dynamical calculations of dissociative adsorption and associative desorption. Using a potential energy surface obtained by density functional theory calculations, we show that the initial decrease of the sticking probability with increasing kinetic energy in the system H2/Pd(100), which is usually attributed to(More)
The sticking and scattering of O(2)Pt(111) has been studied by tight-binding molecular dynamics simulations based on an ab initio potential energy surface. We focus, in particular, on the sticking probability as a function of the angle of incidence and the energy and angular distributions in scattering. Our simulations provide an explanation for the(More)
The dissociative adsorption of hydrogen on Pd(100) has been studied by ab initio quantum dynamics and ab initio molecular dynamics calculations. Treating all hydrogen degrees of freedom as dynamical coordinates implies a high dimensionality and requires statistical averages over thousands of trajectories. An efficient and accurate treatment of such(More)
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