1. Preparation Methods for Nanoparticles and Cluster-Matter by “Physical” Means (U. Kreibig, Aachen) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Nanoparticles and Cluster Matter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2. Cluster-Matter Characterization and Properties . . . . . . . . . . . . . . . . . . . . 4 1.3. Particle Stability ...

The gas phase reaction of Th(+) with H(2)O to produce HThO(+) + H and ThO(+) + H(2) was investigated using density functional theory and coupled cluster methods. RRKM calculations of the branching ratio favor the H atomic elimination channel in disagreement with experiment. Ab initio classical trajectory calculations were carried out to obtain a better model of the molecular dynamics. The molec...

The Xe 5s photoelectron spectrum and 5p(4)nl correlation satellites have been studied in small Xe clusters of an average size of about 15 atoms. The satellite structures are interpreted with the help of the atomic Xe lines. Transition energy shifts between the atomic and the corner/edge/face/bulk components in clusters are divided into polarization screening and exchange interaction energy. Int...

Laser-driven rescattering of electrons is the basis of many strong-field phenomena in atoms and molecules. Here, we will show how this mechanism operates in extended atomic systems, giving rise to effective energy absorption. Rescattering from extended systems can also lead to energy loss, which in its extreme form results in non-linear photo-association. Intense-laser interaction with atomic c...

The far-infrared vibrational spectra for charged vanadium clusters with sizes of 3-15 atoms have been measured using infrared multiple photon dissociation of Vn+Ar-->Vn(+)+Ar. Using density-functional theory calculations, we calculated the ground state energy and vibrational spectra for a large number of stable and metastable geometries of such clusters. Comparison of the calculated vibrational...

We perform a time-delay analysis of of strong field ionization of atomic hydrogen in the tunnelling regime. We obtain the values of the time delay from the quantum-mechanical calculation involving solution of the time-dependent Schrödinger equation, and use these values as parameters defining corresponding classical trajectories. We demonstrate that almost all the classical trajectories, define...

First-principle calculations are employed to show that the magnetic structure of small atomic clusters of Co, formed on a crystalline W(110) surface and containing 3-12 atoms, strongly deviates from the usual stable ferromagnetism of Co in other systems. The clusters are ferri-, ferro- or non-magnetic, depending on cluster size and geometry. We determine the atomic Co moments and their relative...

In this work, we try to build a regression tool to partially replace the use of CPU-time consuming atomic-level procedures for the calculation of point-defect migration energies in Atomistic Kinetic Monte Carlo (AKMC) simulations, as functions of the Local Atomic Configuration (LAC). Two approaches are considered: the Cluster Expansion (CE) and the Artificial Neural Network (ANN). The first is ...

the cluster representation matrices have already been successfully used to enumerate close-packed vacancy clusters in all single-lattice crystals [i, 2]. point defect clusters in double-lattice crystals may have identical geometry but are distinct due to unique atomic postions enclosing them. the method of representation matrices is extended to make it applicable to represent and enumerate the ...

The short range force between the tip and the surface atoms, that is responsible for atomic-scale contrast in atomic force microscopy (AFM), is mainly controlled by the tip apex. Thus, the ability to image, manipulate and chemically identify single atoms in semiconductor surfaces is ultimately determined by the apex structure and its composition. Here we present a detailed and systematic study ...