Hi,
I have a question on restarting simulation. I’m simulating a pairwise potential function molecular dynamic system with cooling condition so that the simulation gives a certain crystalization. I’m restarting the simulation by using multiple ‘run’ command but is there any way to keep temperature change the same when I use multiple run command?
For example, I cool the system from 1.0 to 0.01 for 5000 simulation time using ‘run 50000’ and NVT ensemble ‘fix 1 all nvt 1.0 0.01 1 drag 1.0’.
run 5000 and
run 3000
reset_timestep 3000
run 2000
give different temperature profile. How can I restart the simulation from 3000 with the same temperature as did in ‘run 5000’? Since I want to modify a simulation a little bit at time step 3000 and simulate rest 2000 time step with exactly cooling scheme.
Bests,
Sunhwan
Hi Sunhwan,
For example, I cool the system from 1.0 to 0.01 for 5000 simulation time
using 'run 50000' and NVT ensemble 'fix 1 all nvt 1.0 0.01 1 drag 1.0'.
run 5000 and
run 3000
reset_timestep 3000
run 2000
give different temperature profile. How can I restart the simulation
from 3000 with the same temperature as did in 'run 5000'?
I am not sure if I understand you correctly, but it sounds like you just
have to readjust the Tstart and Tstop values for the two shorter runs. You
can do this by hand (by first raming the temperature from 1.0 to 0.406 for
3000 timesteps, and then from 0.406 to 0.01 for 2000 timesteps), or you
might be able to use the start and stop options of the run command.
Hope this helps,
Lutz
The command fix nvt 1.0 0.01 ...
will ramp the temperature from 1.0 to 0.01 during each run. If you want
to ramp across multiple runs, you need to do what Lutz said.
Steve