Finite-size excess-entropy scaling for simple liquids

Explicit and implicit size effects in computer simulations result from considering systems with a fixed number of particles and periodic boundary conditions, respectively. We investigate these effects in the relation D*(L) = A(L) exp(alpha(L)s(2)(L)) between reduced self-diffusion coefficient D*(L) and two-body excess entropy s2(L) for prototypical simple-liquid systems of linear size L. To this aim, we introduce and validate a finite-size two-body excess entropy integral equation. Our analytical arguments and simulation results show that s2(L) exhibits a linear scaling with 1/L. Since D*(L) displays a similar behavior, we show that the parameters A(L) and alpha(L) are also linearly proportional to 1/L. By extrapolating to the thermodynamic limit, we report the coefficients A(infinity) = 0.048 +/- 0.001 and a8 = 1.000 +/- 0.013 that agree well with the universal values available in the literature [M. Dzugutov, Nature 381, 137-139 (1996)]. Finally, we find a power law relation between the scaling coefficients for D*(L) and s(2)(L), suggesting a constant viscosity-to-entropy ratio. (c) 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).