[gmx-users] charge distribution

Justin A. Lemkul jalemkul at vt.edu
Thu Nov 13 03:40:40 CET 2008

Hongyan Xiao wrote:
> Dear Justin,
> For sodium dodecylbenzenesulfonate(C_ 12 H_25 C_6 H_4 SO_3 Na), the 
> charges of S and O in S0_3^- ^  , I cannot find the suitable charge. 
> Forthermore, the carbon in benzene connecting the SO_3^-  is setted to 
> be zero, I think that there may be questionable. The polarization of 
> SO_3 ^_ -   is very large. what do you think so? 
> Thanks again!

Well, like I said before, QM charges may be a reasonable starting point, but you 
will undoubtedly have to do some empirical fitting; that's how Gromos96 
parameters are derived.  A paper that may interest you regarding SDS parameters 
in simulations:

Schweighofer, K.J., Essmann, U., and Berkowitz, M. (1997) J. Phys. Chem. B. 101: 

That work may provide you with some clues as to a starting point.


> H. Y. Xiao
> ------------------------------------------------------------------------
> _______________________________________________
> gmx-users mailing list    gmx-users at gromacs.org
> http://www.gromacs.org/mailman/listinfo/gmx-users
> Please search the archive at http://www.gromacs.org/search before posting!
> Please don't post (un)subscribe requests to the list. Use the 
> www interface or send it to gmx-users-request at gromacs.org.
> Can't post? Read http://www.gromacs.org/mailing_lists/users.php


Justin A. Lemkul
Graduate Research Assistant
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080


More information about the gromacs.org_gmx-users mailing list