[gmx-users] Re: NaCl

[Vitaly Chaban]

If you simulate such zwitterion with integer charges, the interaction
energy will always be overstated due to electronic polarization, so
the partial volume will always be smaller than experimentalists say.
You may try any ab ibitio method to calculate interaction energy and
partial charges (MK, CHELPG...) and obtain more reasonable energy
values. Then fit them to get the potential of some form.


--
Dr. Vitaly Chaban



On Tue, Aug 17, 2010 at 5:02 PM,  <nishap.patel at utoronto.ca> wrote:
> Hello,
>
>    I want to actually determine the charge effect on partial molar volume. I
> tried using zwitterion glycine, but the partial molar volume that I obtained
> is fairly less than what it should be, so I thought it might be the charge
> effect of two oppositely charged termini, and to understand that better I
> just wanted to use a simple molecule with +ve and -ve charge.
>
>   For the charges, I thought I would put +1 on Na+ and -1 on Cl-. But I
> think I should probably try NaCl crystal like suggested.
>
> Thanks.
>
> -Nisha P
>
>