6533b872fe1ef96bd12d4359
RESEARCH PRODUCT
Kirkwood–Buff integrals of finite systems
Thijs J. H. VlugtNoura DawassJean-marc SimonPeter Krügersubject
Physics010304 chemical physicsBiophysicsFinite system02 engineering and technology021001 nanoscience & nanotechnologyCondensed Matter Physicssmall-systems thermodynamics01 natural sciencesConnection (mathematics)Classical mechanicsKirkwood–Buff integrals0103 physical sciencesPhysical and Theoretical Chemistry0210 nano-technologyMolecular Biologydescription
The Kirkwood–Buff (KB) theory provides an important connection between microscopic density fluctuations in liquids and macroscopic properties. Recently, Krüger et al. derived equations for KB integrals for finite subvolumes embedded in a reservoir. Using molecular simulation of finite systems, KB integrals can be computed either from density fluctuations inside such subvolumes, or from integrals of radial distribution functions (RDFs). Here, based on the second approach, we establish a framework to compute KB integrals for subvolumes with arbitrary convex shapes. This requires a geometric function w(x) which depends on the shape of the subvolume, and the relative position inside the subvolume. We present a numerical method to compute w(x) based on Umbrella Sampling Monte Carlo (MC). We compute KB integrals of a liquid with a model RDF for subvolumes with different shapes. KB integrals approach the thermodynamic limit in the same way: for sufficiently large volumes, KB integrals are a linear function of area over volume, which is independent of the shape of the subvolume.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2018-02-09 | Molecular Physics: an international journal at the interface between chemistry and physics |