We present a model for predicting the free energy of arbitrarily large Mackay icosahedral clusters. van der Waals clusters are experimentally observed to be particularly stable at magic numbers corresponding to these structures. Explicit calculations on the vibrational states were used to determine the spectrum of fundamental frequencies for smaller ~<561! icosahedral clusters. The scaled cumul...

The inverse cascade of energy is a peculiar feature two-dimensional turbulence. Numerical and experimental studies have shown that it possible to produce an also in three-dimensional flow thin layer configuration. Here we study how the friction produced by confining box induces fluctuations which disrupt eventually stop transfer large scales.

The adsorption at the interface between an aqueous solution of several surface-active agents and another fluid (air or oil) phase is addressed theoretically. We derive the kinetic equations from a variation of the interfacial free energy, solve them numerically, and provide an analytic solution for the simple case of a linear adsorption isotherm. Calculating asymptotic solutions analytically, w...

An approximate semianalytic theory is developed to describe the homogeneous nucleation of droplets from a supersaturated vapor, beginning with a partition function and including rigorously the translation and surface tension contributions. The liquid and vapor phases are treated as uniform ~step density profile! and may be described by any accurate equation of state. It is shown that the classi...

The free energy of formation of a droplet in a finite system containing N particles in a box of volume V at a temperature T is examined. For certain values of the supersaturation the free energy of formation has a maximunl and a minimum. The maximum gives rise to a barrier to nucleation whereas the minimum corresponds to the formation of a stable droplet in equilibrium with vapor. Vapor imperfe...

We present first-principles calculations for the atomic structure and energetics of hydrogenated GaN~0001! surfaces. The geometry of the most relevant surface reconstructions is discussed in detail. Finite-temperature effects are included through calculations of the Gibbs free energy and the stability of various surface reconstructions is analyzed in terms of a generalized surface phase diagram...

Based on the Cahn-Hilliard free energy, a thermodynamic model for a reactive binary mixture of incompressible and miscible fluids is derived with a distributed form of surface tension. The model describes chemistry, diffusion, viscosity and heat transfer as well as stresses produced by (and at right angles to) concentration gradients. It allows for a rich spectrum of processes and some of these...

Internet Electron. J. Mol. Des. 2003, 1, 000–000 Abstract In order to separate the effect of substituents into two parts, referring to the interaction of the reacting molecules and the solvation, the δ∆G, δ∆H and δ∆S reaction constants were defined and determined from the dependence of ∆G, ∆H and ∆S activation parameters on the σ substituent constants, by analogy with the Hammett equation. The ...