English

Finite-size estimates of Kirkwood-Buff and similar integrals

Computational Physics 2018-12-04 v2 Soft Condensed Matter Chemical Physics

Abstract

Recently, Kr\"uger and Vlugt [Phys. Rev. E 97, 051301(R) (2018)] have proposed a method to approximate an improper integral 0drF(r)\int_0^\infty \text{d}r\, F(r), where F(r)F(r) is a given oscillatory function, by a finite-range integral 0LdrF(r)W(r/L)\int_0^L \text{d}r\, F(r) W(r/L) with an appropriate weight function W(x)W(x). The method is extended here to an arbitrary (embedding) dimensionality dd. A study of three-dimensional Kirkwood-Buff integrals, where F(r)=4πr2h(r)F(r)=4\pi r^2h(r), and static structure factors, where F(r)=(4π/q)rsin(qr)h(r)F(r)=(4\pi/q) r\sin(qr) h(r), h(r)h(r) being the pair correlation function, shows that, in general, a choice d3d\neq 3 (e.g., d=7d=7) for the embedding dimensionality may significantly reduce the error of the approximation 0drF(r)0LdrF(r)W(r/L)\int_0^\infty \text{d}r\, F(r)\simeq \int_0^L \text{d}r\, F(r) W(r/L).

Keywords

Cite

@article{arxiv.1806.00821,
  title  = {Finite-size estimates of Kirkwood-Buff and similar integrals},
  author = {Andrés Santos},
  journal= {arXiv preprint arXiv:1806.00821},
  year   = {2018}
}

Comments

8 pages, 7 figures; v2: static structure factor included