the molecular geometry of complex of adenine with 8 water molecules was calculated with hartree-fock (hf). the standard 6-31g(d) basis set has been employed. the existence of c-h…o hydrogen bonds between the water molecules and the hydrophobic part of nucleobase is stablished. we optimized structures and computed interaction energies of all complexes of adenine with water molecules step by step...

an analytical equation of state is applied to calculate the thermodynamic properties for argon. theequation of state is that of song and mason. it is based on a statistical-mechanical perturbation theory ofhard convex bodies and can be written as fifth-order polynomial in the density. there exist three temperaturedependentparameters: the second virial coefficient, an effective molecular volume,...

“Umbrella samplmg” has been incorporated in the thermodynamic integration method to obtain a potential of mean force by slow growth molecular-dynamics simulations. The method was tested for liquid argon, for which good agreement was obtained with a standard potential of mean force, as derived from the radial pair-correlation function. For a sodium chloride ion-pair in aqueous solution the calcu...

The aim of thermodynamic integration is to compute the difference in a thermodynamic property (usually the free energy) of the system between some reference state and the state of interest. To measure the free energy change from initial to final state, thermodynamic parameters characterizing the system are changed infinitely slowly so that at each stage along the path the system is in equilibri...

Introduction: the recent discovery of perchlorates (ClO4) by Phoenix triggered a high interest for this rare ion on the surface of the Earth [1]. Indeeed perchlorate solutions have very low eutectic favoring potential liquid water on the surface [2]. The mechanisms by which such a highly oxidized ion formed remain largely unknown. Two major pathways are possible: atmospheric oxidation of aeroso...