Hi Jim,
Try removing jfastwat, don't know if this is even used these days. Then set cut=999, nscm=0 and you should be good.
All the best
Ross
On Jul 1, 2013, at 20:35, "James W. Snyder, Jr." <jsnyder3.stanford.edu> wrote:
> Hi,
>
> I am having a significant amount of trouble running NVE dynamics without substantial temperature and energy drift. My input file is,
>
> &cntrl
> imin = 0,
> cut = 16.0,
> ntb = 0,
> ntc = 1,
> ntf = 1,
> tol = 0.000001,
> irest = 1, !Set to 1 to restart
> ntx = 5, !Set to 5 when you need to restart equil run
> ntpr = 1000, !print detials to log every step
> ntwx = 1000, !write coordinates to mdcrd every step
> ntwr = 1000, !write restart file every step
> ntt = 0,
> jfastw = 4,
> fcap = 0.1,
> ig = -1, !random seed
> t = 0.0,
> nstlim = 1000000,
> dt = 0.001,
> !ifqnt = 1,
> /
> &ewald
> dsum_tol = 0.000001, ! Increase PME accuracy
> /
> END
>
> I've read some forums on this issue, but I have had little success getting the simulation to work properly. I had previously run equilibration in an NVT ensemble for 10ns, and the simulation appears to have converged. Shake does not solve the problem, nor does it seem to help. I can fix the problem by reducing the time step to 0.1fs, but this seems absurdly low. For your reference, the system has roughly 25,000 atoms. Could someone let me know if there are any significant problems with my input?
>
> Thanks,
>
> Jim Snyder
>
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Received on Mon Jul 01 2013 - 21:30:02 PDT
