[gmx-users] charge distribution

[Justin A. Lemkul]

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: 
3793-3799.

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

-Justin

> H. Y. Xiao
> 
>  
> 
> 
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-- 
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Justin A. Lemkul
Graduate Research Assistant
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080
http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin

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