[gmx-developers] Conserved energy drifts more with shorter time steps
hess at kth.se
Tue Jun 2 12:48:18 CEST 2015
So this is not using SETTLE or LINCS?
With SETTLE this is a known issue.
Did you try running NVE?
On 2015-06-02 12:43, David van der Spoel wrote:
> this is in between a user and a developer query. We find that for
> flexible liquid simulations using gromacs 5.0.4/single precision the
> energy conservation gets WORSE with decreasing time step. A plot
> showing this is in
> http://folding.bmc.uu.se/images/Econserved-timestep.xvg or
> MDP settings
> coulombtype = PME
> coulomb-modifier = Potential-shift
> rcoulomb-switch = 0
> rcoulomb = 1.1
> epsilon-r = 1
> epsilon-rf = inf
> vdw-type = PME
> vdw-modifier = Potential-shift
> rvdw-switch = 0
> rvdw = 1.1
> tcoupl = Nose-Hoover
> nsttcouple = 10
> nh-chain-length = 1
> pcoupl = No
> ref-t: 298.15
> tau-t: 0.5
> Any clues whether we are doing something wrong? Or is there a bug?
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