[gmx-users] how small rcoulomb can be

[Gaurav Goel]

For my NPT/NVT simulations I'm using a BKS potential for dispersion
interactions (VdWtype=USER)  which has a cut-off of 0.55 nm. I also
set rcoulomb=rlist=0.55 nm.

My first question is regarding the choice of rcoulomb=0.55nm. Any
thoughts on whether this rcoulomb is large enough to ascertain that
real space electrostatics interactions are fairly small (in comparison
to total coulombic interactions)?

My second question is in regards to doing long (~15-100 ns) NVE
simulations. It appears using coulombtype=PME-Switch will be the best
option to accurately conserve energy. Any thoughts on how to choose
rcoulomb_switch and rcoulomb?

Thanks,
Gaurav