From: Giacomo Fiorin (
Date: Sun Aug 06 2017 - 10:46:37 CDT

Because the charge of the protein comes from adding together many
fractional charges, all represented as floating point charges, it is
difficult to completely add up to an exact multiple of the electron charge.

I'm also not sure whether it's the case, but this link
may be useful as well.


On Sun, Aug 6, 2017 at 10:51 AM, <> wrote:

> Dear vmd users,
> I have a protein solvated in a water box whose net charge is
> 7.999999954365194, so when i am using autoionize to neutralize my system
> it is showing a charge of -4.563480615615845e-8, i also tried to add 8
> chlorine ions instead of going for neutralize option (anyway its more or
> less the same thing), so please kindly help me with this problem.
> regards
> shivam

Giacomo Fiorin
Associate Professor of Research, Temple University, Philadelphia, PA
Contractor, National Institutes of Health, Bethesda, MD