Lattice cluster theory of associating polymers. II. Enthalpy and entropy of self-assembly and Flory-Huggins interaction parameter chi for solutions of telechelic molecules
Jacek Dudowicz, Karl F. Freed, and Jack F. Douglas
The lattice cluster theory for solutions of telechelic polymer chains, developed in paper I, is applied to determine the enthalpy Deltah and entropy Deltas of self-assembly of linear telechelics and to evaluate the Flory-Huggins (FH) interaction parameter chi governing the phase behavior of these sy ... [J. Chem. Phys. 136, 064903 (2012)] published Mon Feb 13, 2012.
Gas-phase structures of neutral silicon clusters
Marko Haertelt, Jonathan T. Lyon, Pieterjan Claes, Jorg de Haeck, Peter Lievens et al.
Vibrational spectra of neutral silicon clusters Si, in the size range of n = 610 and for n = 15, have been measured in the gas phase by two fundamentally different IR spectroscopic methods. Silicon clusters composed of 8, 9, and 15 atoms have been studied by IR multiple photon dissociation spectrosc ... [J. Chem. Phys. 136, 064301 (2012)] published Thu Feb 9, 2012.
Photoionization profiles of metal clusters and the Fowler formula
Abhinav Prem and Vitaly V. Kresin
Metal-cluster ionization potentials are important characteristics of these artificial atoms, but extracting these quantities from cluster photoabsorption spectra, especially in the presence of thermal smearing, remains a big challenge. Here we demonstrate that the classic Fowler theory of surface ph ... [Phys. Rev. A 85, 025201 ] published .
Conformational properties of macromolecular pyramoids and their potential use as nano-containers
M. Kosmas and P. Efthymiopoulos
We study the macroscopic behavior of a pyramid-like nano-construct made of linear macromolecular chains. The average mean square end-to-end distances of the six edges of the pyramoid are evaluated by means of the Gaussian chain model and are found smaller than those of free chains because of archite ... [J. Chem. Phys. 136, 054905 (2012)] published Mon Feb 6, 2012.
Mg impurity in helium droplets
J. Navarro, D. Mateo, M. Barranco, and A. Sarsa
Within the diffusion Monte Carlo approach, we have determined the structure of isotopically pure and mixed helium droplets doped with one magnesium atom. For pure He clusters, our results confirm those of Mella et al. [J. Chem. Phys. 123, 054328 (2005)] that the impurity experiences a transition fro ... [J. Chem. Phys. 136, 054301 (2012)] published Wed Feb 1, 2012.
Binding energy of the positronium negative ion via dimensional scaling
Nikita Blinov and Andrzej Czarnecki
We determine the binding energy of a negative positronium ion in the limits of one spatial dimension and of infinitely many dimensions. The numerical result for the one-dimensional ground-state energy seems to be a rational number, suggesting the existence of an analytical solution for the wave func ... [Phys. Rev. A 85, 012522 ] published .
Efficient Production of Rydberg Positronium
D. B. Cassidy, T. H. Hisakado, H. W. K. Tom, and A. P. Mills, Jr.
We demonstrate experimentally the production of Rydberg positronium (Ps) atoms in a two-step process, comprising incoherent laser excitation, first to the 2 P state and then to states with principal quantum numbers ranging from 10 to 25. We find that excitation of 2 P atoms to Rydberg levels occurs ... [Phys. Rev. Lett. 108, 043401 ] published .
Dynamical cage behaviour and hydrogen migration in hydrogen and hydrogen-tetrahydrofuran clathrate hydrates
Paul D. Gorman, Niall J. English, and J. M. D. MacElroy
Classical equilibrium molecular dynamics simulations have been performed to investigate dynamical properties of cage radial breathing modes and intra- and inter-cage hydrogen migration in both pure hydrogen and mixed hydrogentetrahydrofuran sII hydrates at 0.05 kbar and up to 250 K. For the mixed HT ... [J. Chem. Phys. 136, 044506 (2012)] published Tue Jan 24, 2012.
Mid-infrared spectroscopy of molecular ions in helium nanodroplets
Xiaohang Zhang, Nils B. Brauer, Giel Berden, Anouk M. Rijs, and Marcel Drabbels
High resolution IR spectra of aniline, styrene, and 1,1-diphenylethylene cations embedded in superfluid helium nanodroplets have been recorded in the 3001700 cm range using a free-electron laser as radiation source. Comparison of the spectra with available gas phase data reveals that the helium envi ... [J. Chem. Phys. 136, 044305 (2012)] published Tue Jan 24, 2012.
Effects of static charging and exfoliation of layered crystals
M. Topsakal and S. Ciraci
Using a first-principle plane-wave method we investigate the effects of static charging on the structural, electronic, and magnetic properties of suspended, single-layer graphene, graphane, fluorographene, BN, and MoS in a honeycomb structure. The limitations of periodic boundary conditions in the t ... [Phys. Rev. B 85, 045121 ] published .
Vibrational energy relaxation of benzene dimer and trimer in the CH stretching region studied by picosecond time-resolved IR-UV pump-probe spectroscopy
Ryoji Kusaka, Yoshiya Inokuchi, and Takayuki Ebata
Vibrational energy relaxation (VER) of the Fermi polyads in the CH stretching vibration of the benzene dimer (Bz) and trimer (Bz) has been investigated by picosecond (ps) time-resolved IR-UV pump-probe spectroscopy in a supersonic beam. The vibrational bands in the 30003100 cm region were excited by ... [J. Chem. Phys. 136, 044304 (2012)] published Mon Jan 23, 2012.
Theoretical study of photodetachment processes of anionic boron clusters. I. Structure
S. Rajagopala Reddy and S. Mahapatra
Photo-induced electron detachment spectroscopy of anionic boron clusters, B and B, is theoretically investigated by performing electronic structure calculations and nuclear dynamics simulations. While the electronic potential energy surfaces (X-tildeA, aB, b-tildeB, AB, c-tildeB, and B-tildeB of neu ... [J. Chem. Phys. 136, 024322 (2012)] published Fri Jan 13, 2012.
Theoretical study of photodetachment processes of anionic boron clusters. II. Dynamics
S. Rajagopala Reddy and S. Mahapatra
Photodetachment bands of anionic boron clusters, B (n = 4,5) are theoretically examined here. The model Hamiltonians developed through extensive ab initio quantum chemistry calculations in Paper I are employed for the required nuclear dynamics study. While the precise location of vibronic lines and ... [J. Chem. Phys. 136, 024323 (2012)] published Fri Jan 13, 2012.
Switching from molecular to bulklike dynamics in electronic relaxation of a small gold cluster
Jorg Stanzel, Matthias Neeb, Wolfgang Eberhardt, Polina G. Lisinetskaya, Jens Petersen et al.
We have investigated the ultrafast electronic relaxation of Au using time-resolved photoelectron spectroscopy combined with first-principles simulations of the excited-state dynamics. Unlike previous findings, which have demonstrated molecularlike excited-state relaxation in Au at low excitation ene ... [Phys. Rev. A 85, 013201 ] published .
Influence of the cluster dimensionality on the binding behavior of CO and O on Au
Martin Amft, Borje Johansson, and Natalia V. Skorodumova
We present an ab initio density functional theory study of the binding behavior of CO and O molecules to two- and three-dimensional isomers of Au in order to investigate the potential catalytic activity of this cluster towards low-temperature CO oxidation. First, we scanned the potential energy surf ... [J. Chem. Phys. 136, 024312 (2012)] published Tue Jan 10, 2012.
Weak-to-strong confinement transition of semi-flexible macromolecules in slit and in channel
Peter Cifra
We compare confinement of stiff macromolecule in channel and in slit. Whereas in the channel a distinct and established transition exists, we elucidate here an ongoing controversy reported from previous experiment and simulation on existence of such transition in the slit. Our extensive molecular si ... [J. Chem. Phys. 136, 024902 (2012)] published Mon Jan 9, 2012.
Singly and doubly lithium doped silicon clusters: Geometrical and electronic structures and ionization energies
Nguyen Minh Tam, Vu Thi Ngan, Jorg de Haeck, Soumen Bhattacharyya, Hai Thuy Le et al.
The geometric structures of neutral and cationic SiLi clusters with n = 211 and m = 1, 2 are investigated using combined experimental and computational methods. The adiabatic ionization energy and vertical ionization energy (VIE) of SiLi clusters are determined using quantum chemical methods (B3LYP/ ... [J. Chem. Phys. 136, 024301 (2012)] published Mon Jan 9, 2012.
Core-to-Rydberg band shift and broadening of hydrogen bonded ammonia clusters studied with nitrogen K-edge excitation spectroscopy
Takeshi Yamanaka, Kiyohiko Tabayashi, Osamu Takahashi, Kenichiro Tanaka, Hirofumi Namatame et al.
Nitrogen 1s (N ls) core-to-Rydberg excitation spectra of hydrogen-bonded clusters of ammonia (AM) have been studied in the small cluster regime of beam conditions with time-of-flight (TOF) fragment-mass spectroscopy. By monitoring partial-ion-yield spectra of cluster-origin products, cluster specifi ... [J. Chem. Phys. 136, 014308 (2012)] published Thu Jan 5, 2012.
Beam broadening of polar molecules and clusters in deflection experiments
J. Bulthuis and V. V. Kresin
A beam of rotating dipolar particles (molecules or clusters) will broaden when passed through an electric or magnetic field gradient region. This broadening, which is a common experimental observable, can be expressed in terms of the variance of the distribution of the resulting polarization orienta ... [J. Chem. Phys. 136, 014301 (2012)] published Tue Jan 3, 2012.
Erratum: Collective dipole excitations in sodium clusters [Phys. Rev. A 79, 023202 (2009)]
A. A. Raduta, R. Budaca, and Al. H. Raduta
Abstract not available. [Phys. Rev. A 84, 069909 ] published .
Theoretical characterization of intermolecular vibrational states through the multi-configuration time dependent Hartree approach: The HeICl clusters
Alvaro Valdes, Rita Prosmiti, Pablo Villarreal, and Gerardo Delgado-Barrio
Benchmark, full-dimensional calculations on the ground and excited vibrational states for the tetra-, and penta-atomic weakly bound HeICl complexes are reported. The representation of the potential energy surfaces includes three-body HeICl potentials parameterized to coupled-cluster singles, doubles ... [J. Chem. Phys. 135, 244309 (2011)] published Wed Dec 28, 2011.