WARNING: Fix qeq/reax CG convergence failed after 200 iterations at 1 step and ERROR on proc 0: Non-numeric atom coords - simulation unstable

Dear LAMMPS users,

I’m trying to model a Li-ion battery electrolyte (LiPF6 + C3H4O3) using the ReaxFF forcefield at constant NVT. I’m using “lammps-11Aug17” version of LAMMPS.

I fixed my temperature at 330K with an equilibration run of 120ps during which I get the WARNING: Fix qeq/reax CG convergence failed after 200 iterations at 1 step and the temperature, kinetic energy and pressure outputs nan on screen as shown in the log.lammps file.

The simulation finally aborts leaving the ERROR on proc 0: Non-numeric atom coords - simulation unstable.

Please I will appreciate suggestions on why I have this error and warning

The simplified input is also included in the log.lammps file attached here.

Best regards,

log.lammps (6.46 KB)

This usually means that the geometry of your system is bad. Check for close contacts between atoms.

Michal

Thank you for the quick response, It is indeed helpful. I just changed the data file to one of the data files in the example directory and it ran perfectly without warning or error.

Please how can I generate a good data file for my system.

I used packmol to solvate the ethylene carbonate and lithium hexafluorophosphate which generated a .pdb file I viewed with VNL. I tried to save the solvate as a lammps data but VNL could only save it as atomic atom_style data with the charge (q) column missing, while I am using charge atom_style for my simulation.

Is there a better means I can generate a data file compatible with charge atom_style for my system.?

Best regards,

Some useful links can be found here: http://lammps.sandia.gov/prepost.html

Personally, I would recommend VMD (http://www.ks.uiuc.edu/Research/vmd/) and TopoTools plugin (https://sites.google.com/site/akohlmey/software/topotools) for converting pdb to lammps charge format.

Michal