Size and shape dependence of finite volume Kirkwood-Buff integrals
Soft Condensed Matter
2018-05-23 v2
Abstract
Analytic relations are derived for finite volume integrals over the radial distribution function of a fluid, so-called Kirkwood-Buff integrals. Closed form expressions are obtained for cubes and cuboids, the system shapes commonly employed in molecular simulations. When finite volume Kirkwood-Buff integrals are expanded over inverse system size, the leading term depends on shape only through the surface area to volume ratio. This conjecture is proved for arbitrary shapes and a general expression for the leading term is derived. From this, a new extrapolation to the infinite volume limit is proposed, which converges much faster with system size than previous approximations and thus significantly simplifies the numerical computations.
Keywords
Cite
@article{arxiv.1804.07408,
title = {Size and shape dependence of finite volume Kirkwood-Buff integrals},
author = {Peter Krüger and Thijs J. H. Vlugt},
journal= {arXiv preprint arXiv:1804.07408},
year = {2018}
}