Statistical Mechanics Of Liquids Research Articles

Computing Spatially Resolved Rotational Hydration Entropies from Atomistic Simulations.

For a first-principles understanding of macromolecular processes, a quantitative understanding of the underlying free energy landscape and in particular its entropy contribution is crucial. The stability of biomolecules, such as proteins, is governed by the hydrophobic effect, which arises from competing enthalpic and entropic contributions to the free energy of the solvent shell. While the statistical mechanics of liquids, as well as molecular dynamics simulations, have provided much insight, solvation shell entropies remain notoriously difficult to calculate, especially when spatial resolution is required. Here, we present a method that allows for the computation of spatially resolved rotational solvent entropies via a nonparametric k-nearest-neighbor density estimator. We validated our method using analytic test distributions and applied it to atomistic simulations of a water box. With an accuracy of better than 9.6%, the obtained spatial resolution should shed new light on the hydrophobic effect and the thermodynamics of solvation in general.

Partial molar volume of nonionic surfactants in aqueous solution studied by the KB/3D-RISM–KH theory

Description of self-assembly by means of atomistic models without coarse-graining and empirical adjustment is the most challenging problem in statistical mechanics of liquids. Partial molar volume (PMV) is a thermodynamic property related to effective solvation forces spontaneously driving self-assembly of amphiphilic molecules in solution. We calculate the PMV of several ethylene glycol derivatives, in particular, alkyl polyoxyethylene ethers H(CH2)m−1(CH2OCH2)nCH2OH commonly known as CmEn nonionic surfactants, in aqueous solution at infinite dilution by using the Kirkwood–Buff (KB) equation and the three-dimensional reference interaction site model with the Kovalenko–Hirata closure relation (3D-RISM–KH) integral equation theory of molecular liquids. Special attention is paid to the infinite dilution case since direct measurement of PMV of monomeric surfactants is hindered by their very low critical micelle concentration (cmc). The PMVs obtained from the KB/3D-RISM–KH approach are in good qualitative agreement with experimental data for ethylene glycol derivatives in water at 5; 25; and 45°C.

Functions of Biomolecule Revealed by Statistical Mechanics of Molecular Recognition

Recent progress in the theory of molecular recognition in biomolecules is reviewed, which has been made based on the statistical mechanics of liquids or the 3D-RISM/RISM theory. The molecular recognition of a ligand by the protein is realized by the 3D-distribution functions: if one finds some conspicuous peaks in the distribution of a ligand inside protein, then the ligand is regarded as “recognized” by the protein. 3D-distribution functions can be obtained by means of 3D-RISM/RISM theory. Some biochemical processes are investigated, which are intimately related to the molecular recognition of small ligands such as water, ions, and carbon monoxide by a protein.

Molecular Recognition in Biomolecules Studied by Statistical-Mechanical Integral-Equation Theory of Liquids

Recent progress in the theory of molecular recognition in biomolecules is reviewed, which has been made based on the statistical mechanics of liquids or the RISM/3D-RISM theory during the last five years in the authors' group. The method requires just the structure of protein and the potential energy parameters for the biomolecules and solutions as inputs. The calculation is carried out in two steps. The first step is to obtain the pair correlation functions for solutions consisting of water and ligands based on the RISM theory. Then, given the pair correlation functions prepared in the first step, we calculate the 3D-distribution functions of water and ligands around and inside protein based on the 3D-RISM theory. The molecular recognition of a ligand by the protein is realized by the 3D-distribution functions: if one finds some conspicuous peaks in the distribution of a ligand inside protein, then the ligand is regarded as "recognized" by the protein. Some biochemical processes are investigated, which are intimately related to the molecular recognition of small ligands including water, noble gases, and ions by a protein.

7th Liblice Conference on the Statistical Mechanics of Liquids, Stately Manor Trest, Czech Republic, 11–16 June 2006, http://www.icpf.cas.cz/theory/Liblice

7th Liblice Conference on the Statistical Mechanics of Liquids, Stately Manor Trest, Czech Republic, 11–16 June 2006, http://www.icpf.cas.cz/theory/Liblice

Fifth Liblice Conference on the Statistical Mechanics of Liquids (June 7–12, 1998, Ẑelezná Ruda, Šumava National Park, Czech Republic)

Fifth Liblice Conference on the Statistical Mechanics of Liquids (June 7–12, 1998, Ẑelezná Ruda, Šumava National Park, Czech Republic)

REPORT Fifth Liblice Conference on the Statistical Mechanics of Liquids (June 7-12, 1998, Zelezna Ruda, Sumava National Park, Czech Republic)

REPORT Fifth Liblice Conference on the Statistical Mechanics of Liquids (June 7-12, 1998, Zelezna Ruda, Sumava National Park, Czech Republic)

Fourth Liblice Conference on the Statistical Mechanics of Liquids

Fourth Liblice Conference on the Statistical Mechanics of Liquids

Third Liblice Conference on the Statistical Mechanics of Liquids

Third Liblice Conference on the Statistical Mechanics of Liquids

Solute-solvent interactions - Introductory remarks to the Fourth International Symposium on Solute-Solute-Solvent Interactions

The liquid state is notoriously difficult to describe on a molecular level. This is true for pure liquids as well as for liquid mixtures and solutions. In contrast to the vapor phase and the crystal there is no easy to define idealized model system for the liquid state. In order to overcome this disadvantage combined efforts by theoretical studies and experimental in— vestigations are even more adviseable than in other fields. Therefore, one of the main ideas had been to encourage the dialogue between theorists and experimentalists when the late Prof.Carpeni initiated this series of conferences on specific solute—solvent interactions by organizing the first meeting in Marseille. Six years later these problems have not at all lost their importance. Again it was a predominant goal of the present meeting to bring scientists from different fields together and to initiate further improvement of the molecular interpre— tation of the various phenomena observed in solution chemistry. This is reflected already by the eight plenary lectures presented here which deal with quantum chemical studies on intermolecular forces (H.Lischka), statistical mechanics of liquids (F.Kohler), diffraction studies on ionic solutions (A.H.Narten and R.Triolo), static and dynamic dielectric properties of liquids (L.Sobczyk), infrared and n.m.r. spectroscopy of ionic solutions (M.C.R.Symons), a thermodynamical theory of transport coefficients in dilute ionic solution (J.C.Justice and M.C.Justice), empirical models for solvent effect on chemical reactions (U.Mayer) and specific solvent influences on the mechanisms of inorganic reactions (D.W.Watts).

Statistical mechanics of liquids

Theory of Simple Liquids. By J. Hansen and I. R. McDonald. Pp. xv + 395. (Academic: London and New York, 1976.) £14; $30.65.

Construction and Use of Central Force Models for the Theory of Polyatomic Fluids

AbstractIn order to avoid technical problems posed by nonspherical interactions in the statistical mechanics of liquids, central force models can be devised to describe polyatomic substances. In this approach separate spherical potentials exist for each type of atomic pair. In the case of water, three functions are necessary: VOO(r), VHH(r), and VOH(r); they can be selected so that proper molecules spontaneously form and engage in linear hydrogen bonds. In addition to conventional properties, central force models permit study of molecular vibration and dissociation. Details for NH3, H2O, HF, and CH4 are presented.

Liquid State Physics: A Statistical Mechanical Introduction

Clive A Croxton London: Cambridge University Press 1974 pp x + 421 price £10 Any 'physicist of the world' will know, on picking up a book on the statistical mechanics of liquids, not to expect to learn much about any real liquids save perhaps liquid argon. The practitioners in this field have long learned to compare their theories, which are usually nowadays numerical, with 'experimental' values also generated entirely within computers.

Errata : On the Statistical Mechanics of Liquids, and the Gas of Hard Elastic Spheres

First Page

On the Statistical Mechanics of Liquids, and the Gas of Hard Elastic Spheres

Because of the extreme complications arising from a direct deductive approach, the theory of the liquid state requires the use of a model involving simplifying assumptions. In this paper an attempt is made to formulate general principles which any such model must follow. The first step is a general discussion of ``communal'' entropy, arising from the sharing of available space by all the atoms. Arguments are advanced to support the contention that for a gas of hard elastic spheres the communal entropy is fully excited in each direction of space, and amounts in all to 3R per mole. The communal entropy of assemblages of atoms exerting normal attractive and repulsive forces (in particular, the Debye solid) is considered. The geometry, the equation of state, and the partition function for an assemblage of hard elastic spheres are considered in detail. By extension of these ideas, allowing for the type of force actually exerted on each other by real atoms, a general form of partition function for a monatomic liquid is set up. This partition function involves a sum of two parts, one corresponding to a vibrational motion expressed in terms of the Debye characteristic temperature of the solid, and the other being a translational term, each part carrying with it its own communal entropy.