We prove that the scattering matrix at a fixed quasi–energy determines uniquely a time–periodic potential that belongs to L and that decays exponentially at infinity. Our result is new even in the time–independent case, where it was only proven for bounded exponentially decreasing potentials.

We describe a new stochastic global optimization algorithm, and its application to a class of problems in molecular chemistry. The global optimization problem we consider is to find the lowest minimizer of a nonlinear function f that may contain multiple local minimizers, restricted to a bounded domain where f is assumed to be twice continuously differentiable. The two applications described in...

The microscopic effective pairing interaction in the S0-channel is investigated for two different values of the chemical potential μ starting from the separable form of the Paris NN-potential. It is shown that, within a high accuracy, this effective interaction can be approximated by the off-shell free T -matrix taken at the negative energy E = 2μ.

Different models for effective polarizability in water and the corresponding dispersion forces between dissolved molecules are explored in bulk water and near interfaces. We demonstrate that the attractive part of the Lennard-Jones parameters, i.e., the van der Waals parameter C6 (UvdW ≈ −C6/ρ), is strongly modified when two carbon dioxide (CO2) molecules are near an amorphous silica-water and ...

Using the Gaussian 2003 software and MP2 /6 – 311+ G method for the C2H4 : O2, CO:Cl2 andCO2:CO2 pairs and MP2/6-311++G** method for the CO2:H2O pair and B3lyp/6-31G methodfor the O2:O2 pair the optimized interaction energies between two considered pair molecules ofstudied gases(C2H4:O2, CO:Cl2, CO2:H2O, O2:O2 and CO2:CO2 pairs) as a function of thedistances between the centers of two considere...

We present vapor-liquid phase coexistence curves for binary fluid mixtures in a disordered porous solid. The porous material is modeled as a collection of randomly dispersed hard spheres. A variant of the Monte Carlo Gibbs ensemble method [J. K. Brennan and W. Dong, J. Chem. Phys. 116, 8948 (2002)] is used to simulate Lennard-Jones fluid mixtures at several porosities: 0.9, 0.95, and 0.975. Eff...

Short-range repulsion within intermolecular force fields is conventionally described by either Lennard-Jones (A/r(12)) or Born-Mayer (A exp(-Br)) forms. Despite their widespread use, these simple functional forms are often unable to describe the interaction energy accurately over a broad range of intermolecular distances, thus creating challenges in the development of ab initio force fields and...

The thermal conductivity of several amorphous solids is numerically evaluated within the harmonic approximation from Kubo linear-response theory following the formalism developed by Allen and Feldman. The predictions are compared to the results of molecular dynamics (MD) simulations with realistic anharmonic potentials and to experimental measurements. The harmonic theory accurately predicts th...

Phase changes in 38-atom Lennard-Jones clusters. II: A parallel tempering study of equilibrium and dynamic properties in the molecular dynamics and microcanonical ensembles Abstract We study the 38-atom Lennard-Jones cluster with parallel tempering Monte Carlo methods in the microcanonical and molecular dynamics ensembles. A new Monte Carlo algorithm is presented that samples rigorously the mol...

We report results of a computational study on 2D crystallisation for a 25-particle Lennard-Jones system on a spherical surface, as a function of radius. The energy is minimised using simulated annealing and steepest descent methods. Different crystalline arrangements with clear energy minima are found at different radii. Qualitatively, most of the observed phenomena are representative also for ...