Electronic relaxation dynamics in large anionic water clusters: (HO) and (DO) (n=25200)
Graham B. Griffin, Ryan M. Young, Oli T. Ehrler, and Daniel M. Neumark
Electronic relaxation dynamics subsequent to s-->p excitation of the excess electron in large anionic water clusters, (HO) and (DO) with 25<=n<=200, were investigated using time-resolved photoelectron imaging. Experimental improvements have enabled considerably larger clusters to be probed than in p ... [J. Chem. Phys. 131, 194302 (2009)] published Mon Nov 16, 2009.
An optimized full-configuration-interaction nuclear orbital approach to a hard-core interaction problem: Application to (He)Cl(B) clusters (N<=4)
M. P. de Lara-Castells, P. Villarreal, G. Delgado-Barrio, and A. O. Mitrushchenkov
An efficient full-configuration-interaction nuclear orbital treatment has been recently developed as a benchmark quantum-chemistry-like method to calculate ground and excited solvent energies and wave functions in small doped DeltaE clusters (N<=4) [M. P. de Lara-Castells, G. Delgado-Barrio, P. Vill ... [J. Chem. Phys. 131, 194101 (2009)] published Mon Nov 16, 2009.
Efficient fusion neutron generation from heteronuclear clusters in intense femtosecond laser fields
H. Y. Lu, J. S. Liu, C. Wang, W. T. Wang, Z. L. Zhou et al.
We demonstrate experimentally the efficient fusion neutron generation from Coulomb explosion (CE) of laser irradiated large-size heteronuclear deuterated methane clusters. A conversion efficiency of 2.1 x 10 neutrons/J of incident laser energy is obtained with a 120 mJ, 70 fs laser pulse. It is 50 ... [Phys. Rev. A 80, 051201 (2009)] published Mon Nov 16, 2009.
Bending affects entropy of semiflexible polymers: Application to protein-DNA complexes
Shay M. Rappaport and Yitzhak Rabin
We discuss a class of generalized wormlike chain models of polymers with spontaneous curvature and show that the density of states and consequently the entropy of such natively bent polymers are higher than that of straight ones. This effect changes the classical Langmuir binding isotherm by giving ... [Phys. Rev. E 80, 052801 (2009)] published Thu Nov 12, 2009.
Angular normal modes of a circular Coulomb cluster
L. W. Lupinski and M. J. Madsen
We investigate the angular normal modes for small oscillations about an equilibrium of a single-component Coulomb cluster confined by a radially symmetric external potential to a circle. The dynamical matrix for this system is a Laplacian symmetrically circulant matrix and this result leads to an an ... [J. Math. Phys. 50, 112902 (2009)] published Mon Nov 9, 2009.
Vibrational spectroscopy of neutral silicon clusters via far-IR-VUV two color ionization
Andre Fielicke, Jonathan T. Lyon, Marko Haertelt, Gerard Meijer, Pieterjan Claes et al.
Tunable far-infrared-vacuum-ultraviolet two color ionization is used to obtain vibrational spectra of neutral silicon clusters in the gas phase. Upon excitation with tunable infrared light prior to irradiation with UV photons we observe strong enhancements in the mass spectrometric signal of specifi ... [J. Chem. Phys. 131, 171105 (2009)] published Thu Nov 5, 2009.
Ca impurity in small mixed HeHe clusters
R. Guardiola, J. Navarro, D. Mateo, and M. Barranco
The structure of small mixed helium clusters doped with one calcium atom has been determined within the diffusion Monte Carlo framework. The results show that the calcium atom sits at the HeHe interface. This is in agreement with previous studies, both experimental and theoretical, performed for lar ... [J. Chem. Phys. 131, 174110 (2009)] published Wed Nov 4, 2009.
Ionization dynamics of cluster targets irradiated by x-ray free-electron-laser light
Tatsufumi Nakamura, Yuji Fukuda, and Yasuaki Kishimoto
Interactions of x-ray free-electron laser (XFEL) light with a single cluster target are numerically investigated by using a three-dimensional particle-in-cell code. The plasma dynamics as well as relevant atomic processes are taken into account, such as photoionization, the Auger effect, collisional ... [Phys. Rev. A 80, 053202 (2009)] published Wed Nov 4, 2009.
Experimental observation of effects of seeds on polymer crystallization
Peng-Wei Zhu, Andy Phillips, Graham Edward, and Lance Nichols
The effects of two seeds on the melt crystallization of isotactic polypropylene were experimentally investigated. The seed, which has the flat surface full of a nonuniform size distribution, has provided a right surface pattern to activate effectively the heterogeneous nucleation. In contrast, the s ... [Phys. Rev. E 80, 051801 (2009)] published Tue Nov 3, 2009.
Structures and composition-dependent polarizabilities of open- and closed-shell GaAs semiconductor clusters
Panaghiotis Karamanis, Phillipe Carbonniere, and Claude Pouchan
A systematic investigation of the structures and the dependence of the dipole polarizabilities on the composition of closed and open shell gallium arsenic clusters is presented. Our investigation focuses on nine gallium arsenide (GaAs) clusters with five and six total number of atoms of systematical ... [Phys. Rev. A 80, 053201 (2009)] published Mon Nov 2, 2009.
Enhanced ionization of carbon disulfidedoped heteronuclear clusters in intense laser fields and characterization of the doping level
J. Jha and M. Krishnamurthy
Electron spectra from Ar (n<=24 000) and doped Ar-CS clusters are studied experimentally at laser intensities of about 10 W cm. More than an order of magnitude enhancement in the electron yield is observed in the case of doped Ar-CS clusters. The enhancement observed is argued to be because of the ... [Phys. Rev. A 80, 043202 (2009)] published Wed Oct 21, 2009.
Closed-form evaluation of integrals appearing in positronium decay
Tewodros Amdeberhan, Victor H. Moll, and Armin Straub
A theoretical prediction for the total width of the positronium decay in quantum electrodynamics has been given by Kniehl et al. [Irrational constants in positronium decays, Nucl. Phys. B (Proc. Suppl.) 184, 14 (2008), arXiv:hep-ph/0811.0306] in the form of an expansion in Sommerfeld's fine-structur ... [J. Math. Phys. 50, 103528 (2009)] published Tue Oct 20, 2009.
Collision-induced dissociation studies of FeO : Bond energies in small iron oxide cluster cations, FeO (m=13, n=16)
Ming Li, Shu-Rong Liu, and P. B. Armentrout
A variety of iron oxide cluster cations is synthesized in a laser vaporization ion source. The kinetic energy dependence of the collision-induced dissociation (CID) of mass selected FeO (m=13, n=16) clusters with Xe is studied in this work using a guided ion beam tandem mass spectrometer. Examinatio ... [J. Chem. Phys. 131, 144310 (2009)] published Wed Oct 14, 2009.
Spin-orbit corrections of order malpha to the fine structure of the (37,35) state in the He [overline p] antiprotonic helium atom
Vladimir I. Korobov and Zhen-Xiang Zhong
Precise numerical calculation of radiofrequency intervals between hyperfine sublevels of the (37,35) state of the antiprotonic helium-4 atom is presented. Theoretical consideration includes the QED corrections of order malpha to the electron spin-orbit interaction. Only the leading order contributio ... [Phys. Rev. A 80, 042506 (2009)] published Wed Oct 14, 2009.
Microphase separation of comb copolymers with two different lengths of side chains
M. A. Aliev and N. Yu. Kuzminyh
The phase behavior of the monodisperse AB comb copolymer melt contained the macromolecules of special architecture is discussed. Each macromolecule is assumed to be composed of two comb blocks which differ in numbers of side chains and numbers of monomer units in these chains. It is shown (by analys ... [Phys. Rev. E 80, 041801 (2009)] published Tue Oct 6, 2009.
A theoretical study of water equilibria: The cluster distribution versus temperature and pressure for (HO), n=160, and ice
Annika Lenz and Lars Ojamae
The size distribution of water clusters at equilibrium is studied using quantum-chemical calculations in combination with statistical thermodynamics. The necessary energetic data is obtained by quantum-chemical B3LYP computations and through extrapolations from the B3LYP results for the larger clust ... [J. Chem. Phys. 131, 134302 (2009)] published Fri Oct 2, 2009.
Valence photoionization and the following fragmentation pathways in Sb clusters
S. Urpelainen, A. Calo, L. Partanen, M. Huttula, J. Niskanen et al.
The valence photoelectron spectrum of Sb clusters and the following fragmentation patterns have been studied using synchrotron radiation and electron-ion coincidence technique. An experimental photoelectron spectrum of the 5t ionization of Sb is presented. Theoretical molecular calculations, togethe ... [Phys. Rev. A 80, 043201 (2009)] published Thu Oct 1, 2009.
Effect of the cluster angular momentum J and the projectile orbital momentum L on capture probability and postcollision dynamics
Massimo Mella
In this work, collisions between rotating atomic clusters composed of Lennard-Jones (LJ) particles and an identical projectile have been investigated by means of trajectory simulations as a function of the cluster angular momentum J and internal energy E, and for different values of the projectile i ... [J. Chem. Phys. 131, 124309 (2009)] published Wed Sep 30, 2009.
The discovery of unexpected isomers in sodium heptamers by BornOppenheimer molecular dynamics
Jose Manuel Vasquez-Perez, Gabriel Ulises Gamboa Martinez, Andreas M. Koster, and Patrizia Calaminici
This work presents a density functional study of neutral, cationic, and anionic sodium cluster heptamers. The cluster structures were optimized with the local density approximation as well as with the generalized gradient approximation. For the neutral and cationic clusters new unexpected isomers ar ... [J. Chem. Phys. 131, 124126 (2009)] published Wed Sep 30, 2009.
Single surface beyond BornOppenheimer equation for a three-state model Hamiltonian of Na cluster
Amit Kumar Paul, Subhankar Sardar, Biplab Sarkar, and Satrajit Adhikari
When a set of three states is coupled with each other but shows negligibly weak interaction with other states of the Hilbert space, these states form a sub-Hilbert space. In case of such subspace [J. Chem. Phys. 124, 074101 (2006)], (a) the adiabatic-diabatic transformation (ADT) condition, [del]-ve ... [J. Chem. Phys. 131, 124312 (2009)] published Wed Sep 30, 2009.
AlH: Hydrogen atom site selectivity and the shell model
A. Grubisic, X. Li, S. T. Stokes, K. Vetter, G. F. Gantefor et al.
Using a combination of anion photoelectron spectroscopy and density functional theory calculations, we explored the influence of the shell model on H atom site selectivity in AlH. Photoelectron spectra revealed that AlH has two anionic isomers and for both of them provided vertical detachment energi ... [J. Chem. Phys. 131, 121103 (2009)] published Fri Sep 25, 2009.