if expression in run/every command

Hello everybody,

I'd like to implement a conditional run-command.

The background is the following:
I'm using the fix dt/reset to increase my timesteps during periods when nothing happens in my simulation. Thus it would be wrong to tell LAMMPS "run N" if I want to run that simulation e.g. 2 seconds - because N is a number and doesn't change relative to the increasing timestep dt.
So I tried the following:

fix timestepping all dt/reset 1 1e-5 2e-5 2.5e-8 units box
variable cum_simtime equal f_timestepping[1]
run N every 10 "if ${cum_simtime} >= 0.0004 then "jump SELF Periode2""

It seems that nesting the quotes doesn't work in that example and LAMMPS exits the run-command at the second ".

Has anybody an idea how I could implement that?

Thanks in advance,
kind regards


You can use single or double quotes and have one level
of nesting, so I would try that. See Section 3.2 of the manual for