> I would expect the values to be identical in both cases since I am
> restarting my simulation with the same coordinate and velocity
> values at this particular time step supplied through restart file.
> I think Dan's reply is wrong in this case. The more likely culprit is that
> saving to a restart file, then restarting loses some precision. When running
> MD, small differences in starting coordinates (or velocities)
> quickly produces
> divergent trajectories. This is discussed in the "testing" section of the
> Users' Manual.
> To see what happens with a restart, run a short simulation (say 500 steps)
> with ntpr=1, then break it into two parts, again with ntpr=1. You should
> see initial agreement, but by 500 steps, things generally will have
> diverged.
> ....hope this helps....dac
Well thank you Dan and Dac for your responses. In fact I need to thank
Dac for his responses to my other previous posts in the list.
I will perform the exercise to check out the difference. But then if
this is the case, I will be expecting divergent trajectories in cases
when I will have my job restarted as compared to the run which will be
undisturbed.
Also the trajectories will be divergent if I run one long simulation
or divide the simulation into multiple parts during the run.
Dilraj.
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Received on Sun Feb 26 2012 - 03:00:02 PST
