How to use multiple time steping in gmx2021

User discussions
1

GROMACS version: 2021

Hello,
I am very interested in trying out the multiple time steping option of gmx2021. Unfortunatelly, I can’t really find any information on how to use it a part from the mdp param page which just explains the syntax. For example: Right now I am using the CHARMM-ff with 2fs and constrains on H-bonds and SETTLED waters. Should I just use the same timestep and calculate the long-range PME every 4 fs?
Thank you very much for your help!
Best,
Sergio

2

Yes, doing PME every 4 fs is what many other codes do.

I had intended to compute more interactions only every 4 fs, but that seems to lead to (very rarely occurring) instabilities, with the Amber, and possibly also the Charmm, force field.

3

Got it! Thanks a lot Berk!
Best,
Sergio