Optimizing the photoassociation of cold atoms by use of chirped laser pulsesPhotoassociation of ultracold atoms induced by chirped picosecond pulses is analyzed in a non-perturbative treatment by following the wavepackets dynamics on the ground and excited surfaces. The…Eliane Luc-Koenig, Mihaela Vatasescu, Francoise Masnou-Seeuws·Jul 21, 2004SaveLearn
Global minima of AlN, AuN and PtN, N=2-80, clusters described by Voter-Chen version of embedded-atom potentialsUsing the basin-hopping Monte Carlo minimization approach we report the global minima for aluminium, gold and platinum metal clusters modelled by the Voter-Chen version of the embedded-atom model…Ali Sebetci, Ziya B. Guvenc·Jul 20, 2004SaveLearn
Discovery of dumbbell-shaped Cs*Hen exciplexes in solid He 4We have observed several new spectral features in the fluorescence of cesium atoms implanted in the hcp phase of solid helium following laser excitation to the 62P states. Based on calculations…D. Nettels, A. Hofer, P. Moroshkin et al.·Jul 15, 2004SaveLearn
Electron--phonon coupling and anharmonic effects in metal clustersThe periods of the harmonic oscillations of the ion core of charged sodium clusters around the equilibrium shapes are considered. It is found that these periods are of the order of magnitude of the…F. F. Karpeshin, J. da Providencia, C. Providencia et al.·Jul 15, 2004SaveLearn
Polarization forces in water deduced from single molecule dataIntermolecular polarization interactions in water are determined using a minimal atomic multipole model constructed with distributed polarizabilities. Hydrogen bonding and other properties of…Eugene V. Tsiper·Jul 8, 2004SaveLearn
Electronic structure, vibrational stability, infra-red, and Raman spectra of B24N24 cagesWe examine the vibrational stability of three candidate structures for the B24N24 cage and report their infra-red (IR) and Raman spectra. The candidate structures considered are a round cage with…Rajendra R. Zope, Tunna Baruah, Mark R. Pederson et al.·Jul 6, 2004SaveLearn
Small rare gas clusters in laser fields: ionisation and absorption at long and short laser wavelengthsThe interaction of short laser pulses with small rare gas clusters is investigated by using a microscopic, semi-classical model with an explicit treatment of the inner-atomic dynamics. Field and…D. Bauer·Jun 28, 2004SaveLearn
Free Energy Approach to the Formation of an Icosahedral Structure during the Freezing of Gold NanoclustersThe freezing of metal nanoclusters such as gold, silver, and copper exhibits a novel structural evolution. The formation of the icosahedral (Ih) structure is dominant despite its energetic…H. -S. Nam, Nong M. Hwang, B. D. Yu et al.·Jun 23, 2004SaveLearn
Fission of charged alanine dipeptidesIn this work we have performed for the first time a systematic analysis of the dissociation and fission pathways of neutral, singly and doubly charged alanine dipeptide ions with the aim to identify…Alexander V. Yakubovitch, Ilia A. Solov'yov, Andrey V. Solov'yov et al.·Jun 21, 2004SaveLearn
Conformational properties of neutral and charged alanine and glycine chainsWe have investigated the potential energy surface for neutral and charged alanine and glycine chains consisting of up to 6 amino acids. For these molecules we have calculated potential energy…Alexander V. Yakubovitch, Ilia A. Solov'yov, Andrey V. Solov'yov et al.·Jun 21, 2004SaveLearn
Infrared electron modes in light deformed clustersInfrared quadrupole modes (IRQM) of the valence electrons in light deformed sodium clusters are studied by means of the time-dependent local-density approximation (TDLDA). IRQM are classified by…V. O. Nesterenko, P. -G. Reinhard, W. Kleinig et al.·May 3, 2004SaveLearn
Using Static Charge on Pyroelectric Crystals to Produce Self Focusing Electron and Ion Beams and Transport Through TubesStatic charge in and on the surface of pyroelectric crystals of LiNbO3 and LiTaO3 in a dilute gas has been shown to ionize gas molecules via electron tunneling. The released electrons and positive…James D. Brownridge, Stephen M. Shafroth·Apr 23, 2004SaveLearn
Photoassociation of cold atoms with chirped laser pulses: time-dependent calculations and analysis of the adiabatic transfer within a two-state modelThis theoretical paper presents numerical calculations for photoassociation of ultracold cesium atoms with a chirped laser pulse and detailed analysis of the results. In contrast with earlier work,…E. Luc-Koenig, R. Kosloff, F. Masnou-Seeuws et al.·Apr 7, 2004SaveLearn
Taming the rugged landscape: production, reordering, and stabilization of selected cluster inherent structures in the X(13-n)Yn systemWe present studies of the potential energy landscape of selected binary Lennard-Jones thirteen atom clusters. The effect of adding selected impurity atoms to a homogeneous cluster is explored. We…Dubravko Sabo, J. D. Doll, David L. Freeman·Mar 22, 2004SaveLearn
Variational Estimates using a Discrete Variable RepresentationThe advantage of using a Discrete Variable Representation (DVR) is that the Hamiltonian of two interacting particles can be constructed in a very simple form. However the DVR Hamiltonian is…M. Lombardi, P. Barletta, A. Kievsky·Mar 11, 2004SaveLearn
Silicon clusters produced by femtosecond laser ablation: Non-thermal emission and gas-phase condensationNeutral silicon clusters Sin (up to n = 7) and their cations Sin+ (up to n = 10) have been produced by femtosecond laser ablation of bulk silicon in vacuum and investigated using time-of-flight…Alexander V. Bulgakov, Igor Ozerov, Wladimir Marine·Mar 10, 2004SaveLearn
Cluster emission under femtosecond laser ablation of siliconRich populations of clusters have been observed after femtosecond laser ablation of bulk silicon in vacuum. Size and velocity distributions of the clusters as well as their charge states have been…Alexander V. Bulgakov, Igor Ozerov, Wladimir Marine·Mar 10, 2004SaveLearn
Composition-induced structural transitions in mixed rare-gas clustersThe low-energy structures of mixed Ar--Xe and Kr--Xe Lennard-Jones clusters are investigated using a newly developed parallel Monte Carlo minimization algorithm with specific exchange moves between…F. Calvo, E. Yurtsever·Mar 8, 2004SaveLearn
Stability of Asn [n=4, 8, 20, 28, 32, 36, 60] Cage StructuresWe present all-electron density functional study of the geometry, electronic structure, vibrational modes, polarizabilities as well as the infrared and Raman spectra of fullerene-like arsenic cages.…Tunna Baruah, Mark R. Pederson, Rajendra R. Zope et al.·Feb 19, 2004SaveLearn
Are hemispherical caps of boron-nitride nanotubes possible?We report all-electron, density-functional calculations with large Gaussian polarization basis set of the recently synthesized octahedral B24N24 cage that is perfectly round by symmetry, and…Rajendra R. Zope, Brett I. Dunlap·Feb 19, 2004SaveLearn
Molecular structures and vibrations of neutral and anionic CuOx (x = 1-3,6) clustersWe report equilibrium geometric structures of CuO2, CuO3, CuO6, and CuO clusters obtained by an all-electron linear combination of atomic orbitals scheme within the density-functional theory with…Tunna Baruah, Rajendra R. Zope, Mark R. Pederson·Feb 19, 2004SaveLearn
Electron diffraction data on structural transformations in free clucters of argonAn electron diffraction technique is used to study the structure of clusters formed in an isentropically expanding supersonic argon jet. The formation of the hcp phase with increasing cluster size is…Spartak I. Kovalenko, Oleksandr G. Danylchenko, Vladimir N. Samovarov·Feb 12, 2004SaveLearn
Momentum transfer to small particles by aloof electron beamsThe force exerted on nanoparticles and atomic clusters by fast passing electrons like those employed in transmission electron microscopes are calculated and integrated over time to yield the momentum…F. J. Garcia de Abajo·Feb 2, 2004SaveLearn
Sodium atoms and clusters on graphite: a density functional studySodium atoms and clusters (N<5) on graphite (0001) are studied using density functional theory, pseudopotentials and periodic boundary conditions. A single Na atom is observed to bind at a hollow…K. Rytkonen, J. Akola, M. Manninen·Jan 20, 2004SaveLearn
DFT Study of Nitroxide Radicals. 1. Effects of solvent on structural and electronic characteristics of 4-amino-2,2,5,5-tetramethyl-3-imidazoline-N-oxylImidazoline-based nitroxide radicals are often used as spin probes for medium acidity and polarity in different systems. In this work, using the density functional theory (DFT) approach, we have…Larissa N. Ikryannikova, Leila Yu. Ustynyuk, Alexander N. Tikhonov·Dec 22, 2003SaveLearn