[gmx-developers] problems with trajectory reversal

[Berk Hess]

> > Is there an easy way of reversing my trajectory or should I somehow
> > modify the code to get proper results? What is Gromacs doing with the
> > kinetic energy at the initialisation that it seems to increase ?
>
>If you use twin-range cutoff with nstlist > 1, your trajectory will not
>be reversible in principle, due to the interval between updating long-
>range forces. Also, I think constraints may be problematic upon momenta
>inversion (not sure about this, though).

Constraints are not a problem.

But more importantly the velocities in the input and output are at t-dt/2.
So to run in reverse you would need to take the coordinates
from frame t and the velocities from frame t+dt.

Berk.

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