[gmx-users] Extending a run and changing nstxout

[Andrew DeYoung]

Hi,

I would like to extend a run.  I ran a 10 ns simulation, and I would like to
run the simulation for an additional 10 ns.  Normally I would do this with
the following two commands:

tpbconv -s topol_old.tpr -o topol_new.tpr -extend 10000
mdrun -cpi checkpoint_old.cpt -s topol_new.tpr -noappend

where topol_old.tpr is the original .tpr file and checkpoint_old.cpt is the
last checkpoint file saved in the original run.  (The -noappend option means
that the additional 10 ns (t = 10 ns to t = 20 ns) will be put in a separate
.trr file.)

However, I am running out of disc space and I would like to reduce the
frequency with which I save configurations; I would like to use nstxout =
200 instead of nstxout = 50 as in the original run.  Is there any way that I
can use tpbconv or a similar utility to change the value of nstxout in
topol_old.tpr?

Thanks!

Andrew DeYoung
Carnegie Mellon University