Re: [AMBER] Dielectric asymptotic parameter of mixtures for DRISM in rism1d

From: Tyler Luchko (Lists) <"Tyler>
Date: Wed, 20 Jul 2016 10:48:34 -0700

> On Jul 19, 2016, at 11:14 PM, Shijie Sheng <> wrote:
> Hi,
> I carefully checked the code of rism1d and the existing literature
> about the dielectric constant relation to correlation functions, and found
> an inconsistency in hc(k).
> According to the code (line 397 to line 407 of
> rism1d_potential_c.F90) based on the seminal article of Perkyns and Pettitt
> (JCP,97:7656), the hc(k) is calculated through Eq.(34) from that article.
> My question is that if the equation still holds true for mixtures. I ask
> this question because hc(k) is interpreted differently in Eq.(9)~(12) of
> Kvamme's article (Interaction-site Representation of polar mixtures and
> electrolyte solutions). I was wondering which one is correct for
> *mixtures. *

I recommend looking at
B. Kvamme, Phys. Chem. Chem. Phys. 4, 942 (2002)
Eq. 5 and
M. Holovko, A. Kovalenko, and F. Hirata, Journal of Molecular Liquids 217, 103 (2016)
between Eq. 10 and 11, where the notation is a little clearer, IMO. This is what is implemented in the lines you cite and is Kvamme’s extension of DRISM to mixtures.

> * Plus, *the bridge output in rism1d is not reasonable to me. For
> example, when one uses DRISM/HNC, none zero bridge functions should be
> obtained. The HNC closure is in the sense of C_H\equivC-b not the direct
> correlation function C. However, the bridge term is set to zero in
> rism1d_hnc_c.F90.

I’m not sure what you mean here. The general closure equation is given by

g(r) = exp[ -\beta u(r) + h(r) - c(r) + b(r)]

where b(r) is the bridge function. In HNC b(r) = 0.

I hope this helps,

AMBER mailing list
Received on Wed Jul 20 2016 - 11:00:03 PDT
Custom Search