Interpolating the Radial Distribution Function in Two-Dimensional Fluid Across a Wide Temperature Range

Abstract

Calculations of pair correlations in fluids usually require resource-intensive simulations or integral equations, while existing simple approximations lack accuracy. In this article, we propose a Fluid Interpolating Method (FIM) for reconstructing radial distribution function (or g(r)) in simple liquids and liquid-like systems over a wide temperature range. The core concept of the method is to decompose g(r) into the contributions provided by the correlation spheres identified with the shortest-graphs through the neighboring Voronoi cells. With computer simulations, we observed that these correlation peaks (excluding the first one), being properly normalized, closely resemble those of an ideal gas, thus, indicating just a weak dependence on the temperature and on the particular profile of the interaction potential. We show that the normalization parameters for these peaks can be accurately interpolated across a broad temperature range, using structure data of the fluid at three temperature points only. The generality of the proposed approach is validated with diverse 2D fluid-like systems with different interactions between particles, (i) LJ fluids at different densities, (ii) fluid of particles with soft 1/r^3-inverse-power-law repulsion (IPL3-fluid), and (iii) hard 1/r^{96}-inverse-power-law repulsion (IPL96-fluid), (iv) active fluid of particles with Langevin dynamics, and (v) model "cellular fluid'' of biological tissue described within Potts' framework. The simplicity and unexpectedly high accuracy of the proposed framework pave the way for its application in future theoretical studies and analysis of experiments with fluids of different nature. The study was supported by the Russian Science Foundation, Grant No. 20-72-10161.

Speaker

Ilya R. Denisenko
Bauman Moscow State Technical University, 2nd Baumanskaya street 5, 105005 Moscow, Russia
Russia

Discussion

Ask question