Inquiry on Restart and Fix Deform

Dear Dr. Axel Kohlmeyer,

Hello Dr. Kohlmeyer. Thank you for your many advice.

When you previously discussed, “watch out when restarting in the middle of a gradual change. have a close look at the documentation for the run command,”
I am not sure why atoms in the data file are being migrated beyond the cutoff distance of the FENE potential thereby giving me BAD FENE BONDS error when I restart a simulation during a middle of gradual change. (I am using the same number of processors in my restart file.)

This seems to be a trivial issue; however, I tried a following simple case:

Case 1: Run a stress-strain simulation where the elongation of the simulation box is determined by:

fix 4 all deform 1 x erate 0.01 y volume z volume

run 10000 upto

Then run a restart simulation during the middle of this run, say at 4000 timesteps where the fix deform is re-specified as

fix 4 all deform 1 x erate 0.01 y volume z volume

run 10000 upto

Restart simulation runs smoothly without issues

Case 2: Run a stress-strain simulation where the elongation of the simulation box is determined by:

variable displace equal “0.01stepdt”
variable rate equal “0.01”

fix 4 all deform 1 x variable v_displace v_rate y volume z volume remap v

run 10000 upto

Then, run a restart simulation during the middle of this run, say at 4000 timesteps where the fix deform is re-specified as the same,

variable displace equal “0.01stepdt”

variable rate equal “0.01”

fix 4 all deform 1 x variable v_displace v_rate y volume z volume remap v

Restart simulation experiences FENE bond too long

Both of these simple cases should output the same results since I am not changing anything to the deformation. I tried using the start/stop option of the run command; however, I am still obtaining the BAD FENE BONDS error.

Thank you so much for all of your previous assistance. I would greatly appreciate if I could, once again, request for your advice in pointing me to the correct direction. Thank you so much for your time and effort.

Sincerely,

Masato Koizumi

you don’t seem to be paying attention. that is not good, if you want to become a good scientists.
so here it is one more time and more explicitly.

i am not your adviser, i am not your tutor and it is not my job to teach you how to do research.

you have already more than exploited my good will to help you regardless and way outside of what are LAMMPS specific issues.

axel.