[gmx-users] Timestep in GROMACS simulation

[Kevin Boyd]

Hi,

That totally depends on your forcefield. Most classical all-atom
forcefields are recommended to be run with a 2 femtosecond timestep.
Some coarse-grained forcefields like Martini can do 20+ fs, but you’ll
want to check the literature.

As for better sampling, you simply sample longer times for the same
number of steps. There's no real per-step performance penalty for
increasing the timestep, so if each step you take is 10x longer, and
you have the same number of steps, you've simulated 10x more time.

Kevin

Kevin

> On May 28, 2019, at 8:35 PM, Anh Vo <atv55 at msstate.edu> wrote:
>
> Hi all,
>
> How did you choose your timestep and simulation time when running GROMACS?
> Is there any logic for deciding that?
> I’ve read that larger time step permits better sampling without significant
> errors in observed thermodynamic, structural or dynamic properties => What
> does “sampling” mean? Why does the larger time step allow better sampling?
>
> Thank you a lot.
>
> Best,
> Anh Vo
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