A universal, i.e., not dependent on the Hamiltonian of the two-particle interaction, expansion of the equilibrium three-particle distribution function with respect to the two-particle correlation functions is constructed. A diagram technique that permits systematic calculation of the coefficients of this expansion is proposed. In particular, it is established that allowance for the first four o...

Dielectric relaxation measurements on Methanol – Dimethylaminoethanol solvent mixtures have been carried out across the entire concentration range using Time Domain Reflectometry technique at 15, 25, 35 and 45C over the frequency range from 10 MHz to 20 GHz. The mixtures exhibit a principle dispersion of the Davidson-Cole relaxation type at microwave frequencies. The Bilinear calibration method...

Dielectric properties are evaluated by means of molecular dynamics simulations on two model systems made up of dipolar molecules. One of them mimics methanol, whereas the other differs from the former only in the ability to form hydrogen bonds. Static dielectric properties such as the permittivity and the Kirkwood factor are evaluated, and results are analyzed by considering the distribution of...

The theory of dielectrics brought in by Onsager [1], which takes into account the interaction between molecules and their environment, though applicable to pure polar liquids, is inadequate to justify the behaviour of some liquids whose molecules exhibit associating properties, such as acids, alcohols, amides and cyanides. This inadequacy led Kirk­ wood [2] to hypothesize an orientational corre...

Abstract We considered a long-range Ising model under Glauber dynamics and calculated the difference from mean-field approximation in finite-size system using perturbation theory. To deal with Bogoliubov–Born–Green–Kirkwood–Yvon hierarchy, we assumed that certain types of extensive properties have Gaussian distribution, which turned out to be equivalent Kirkwood superposition within range first...

A theoretical approach to calculate the correlation functions in binary hard-sphere (HS) solid mixtures is developed. The method is motivated by the theory of correlations in one-component HS solids [Rascon, Phys. Rev. E 54, 1261 (1996)] and the Kirkwood-Buff theory for solutions. Combined with the fundamental measure density functional theory the approach provides correlation functions in good...

Fractional Brownian motion (fBm) is a ubiquitous nonstationary model for many physical processes with power-law time-averaged spectra. In this paper, we exploit the nonstationarity to derive the full spectral correlation structure of fBm. Starting from the time-varying correlation function, we derive two different time-frequency spectral correlation functions (the ambiguity function and the Kir...

An analytic argument is given to show that the application of the Kirkwood superposition approximation to the description of fluid correlation functions precludes the existence of a critical point. The argument holds irrespective of the dimension of the system and the specific form of the interaction potential and settles a long-standing controversy surrounding the nature of the critical behavi...