[gmx-users] partial charges leading to non-zero total charge/floating point arithmetic
Shayna Hilburg
shilburg at mit.edu
Mon Apr 23 16:29:35 CEST 2018
Hi all,
I'm setting up a system and I am getting a non-zero total charge of
approximately 0.0002. I have several thousand ions in a system where the
cation is a single atom of charge +2, and then the anion is a CO3 molecule
(C with +1.3 and O with -1.1). If I change the partial charges to be full
charges (C with +1 and O with -1), there is no longer a non-zero total
charge.
According to the error documentation, I understand this is probably due to
floating point arithmetic, but I do not understand fully which calculation
might be causing it and what technique I should take to have a neutral
system. I am running in a low dielectric medium so I think the slight net
charge could be an issue. Any suggestions would be appreciated!
Thanks!
-Shayna
More information about the gromacs.org_gmx-users
mailing list