Continue simulation at current fixed settings (bump)

Hi,

Re-submitting a previous question I still need an answer to.

What is the advised means with which to just "continue" a run at current fixed settings for
a given amount of time. The situation I have is that I have to first equilibrate my system through a succession of fixes on the different components/groups, but wish to then just run the simulation for a set amount of time after these fixes have completed.

Paraphrasing my code slightly:

...

lmp.command('fix 2 network npt temp 0.02 0.23 $(100.0*dt) iso 0.05 0.05 1')

lmp.command('run 10000')

lmp.command('fix 3 bilayer nvt/asphere temp 0.02 0.23 $(100.0*dt)')

lmp.command('run 10000')

"fix 4 / command to then go here"

lmp.command('run 40000')

So to summarize, I have to equilibrate my network group first over a temperature ramp, then similarly equilibrate my bilayer group over another temperature ramp. I then wish to just have the simulation continue running (probably with the nvt/asphere fix) at T=0.23 and P=0.05 for say 40000 more steps, to analyse its now resting state.

So far I have tried just setting a new bilayer fix with fixed temperature, and/or unfixing the previous fixes, but both seem to mess up. If I unfix 3, the whole thing freezes up.

Is there just a way to write my "fix 3 bilayer ..." such to have it continue running for another X steps after it has ramped up from T=0.02 to 0.23? At the moment, the ramp will stretch itself over the full number of runs, but I just want it to have a fixed rate of increase.

Thanks,

Paul

Is there just a way to write my “fix 3 bilayer …” such to have it continue running for another X steps after it has ramped up from T=0.02 to 0.23? At the moment, the ramp will stretch itself over the full number of runs, but I just want it to have a fixed rate of increase.

just run the first part with a ramp and then *replace* the fix with
one that has a constant temperature. there is nothing special or
particular there. you just need to study and follow the documentation
of the fix commands and the generic fix and run command docs
carefully.

axel.