Current temperature too close to zero, consider using ptemp setting


I’m trying to simulate the elastic properties of silica at extreme low temperatures (at 1 K in this case). I’m working with reaxff potentials and also incorporating the QTB package to account for the quantum effects that are known to be important in this temperature regime.

I have managed to run a couple of simulations successfully with version 3 March 2020, however I’ve recently reinstalled Lammps and now I’m working with 30 Jun 2020 version. Now the exact same script that was running without any problems previously gives me this error:

ERROR: Current temperature too close to zero, consider using ptemp setting (…/fix_nh.cpp:787)

I searched for this error but couldn’t find any previous instances - I hope I’m not missing anything.

I have attached my input file, and the two different output files I got with these two different versions for the same input file. I would really appreciate it if I can get some feedback on why I’m getting this error, and hear if there is any other solution than reinstalling a previous version that I know my scripts run without problems.

Thank you very much,
Karsu Kilic

3March.out (349 KB)

30June.out (1.85 KB)

in.SiO2 (2.81 KB)

This is due to this change:
please read the explanation and the corresponding section of the manual.
you will need to set the ptemp flag similar to what is done in the (correspondingly updated) examples.