Orientational effects in rotationally elastic collisions of OH with Ar were studied in a crossed molecular beam setup. A static electric field was applied to orient the molecules before the collision. After the collision the orientation was measured by using a narrow-band laser system to probe the Stark-split states corresponding to different orientations. Differential and integral cross sectio...

Estimates for the lifetime of collision complexes formed during ultracold molecular collisions based on density-of-states arguments are shown to be consistent with similar estimates based on classical trajectory calculations. In the classical version, these collisions are shown to exhibit chaos and their fractal dimension is calculated versus collision energy. From these results, a picture emer...

As recently proposed, the long-time behavior of equilibrium time-correlation functions for one-dimensional systems are expected to be captured by a nonlinear extension of fluctuating hydrodynamics. We outline the predictions from the theory aimed at the comparison with molecular dynamics. We report on numerical simulations of a fluid with a hard-shoulder potential and of a hard-point gas with a...

We study the collision of a DNA or other polyelectrolyte chain with a point obstacle in the presence of an electric field via computer simulation. We find a very strong dependence of the average collision time, ktcl, and the average distance traveled during a collision, kzcl, upon the impact parameter, b. Despite the complexities of the chain-post interaction, ktcl and kzcl follow universal cur...

Molecular Dynamics simulations are carried out for investigating atomic processes of platinum sputtering. Sputtered Pt atom energy distribution functions (EDF) are determined at different sputtering argon ionenergies: 100, 500, and 1000 eV. Calculated EDF show a cross-over from Thompson theory to binary collision model when increasing argon ion energy and Pt atom sputtered energy. Implanted arg...

The collision of two water tetramers is investigated with classical molecular dynamics and an empirical potential function. Varying the impact parameter, collision and internal energies of the two colliding tetramers we explore the possibility of forming the cubic structure isomers of the octamer. We ®nd that such events are favored under small collision energies and impact parameters with cold...

As a further theoretical study of the collision-induced quantum interference on rotational energy transfer in an atom-diatom system, the differential interference angles for singlet-triplet mixed states of Na2 system in collision with He were calculated based on the first-Born approximation of time-dependent perturbation theory, taking into account the anisotropic Lennard-Jones interaction pote...

Cold, neutral hydroxyl radicals are Stark decelerated and efficiently loaded into a permanent magnetic trap. The OH molecules are trapped in the rovibrational ground state at a density of approximately 10;{6} cm;{-3} and temperature of 70 mK. Collision studies between the trapped OH sample and supersonic beams of atomic He and molecular D2 determine absolute collision cross sections. The He-OH ...

für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namen...

Collision phenomena are ubiquitous and of importance in determining the microscopic structures intermolecular interactions atoms molecules. The existing approaches mostly based on atomic or molecular scatterings, which hindered by inconvenience using ultra-high vacuum low temperature systems. Here we demonstrate a new spin-noise spectroscopic approach measuring optical polarization rotation noi...