Hello LAMMPS users,
I am trying to perform MD simulation using Reactive Forcefield, however, my initially constructed system is not charge neutral (overall charge is -20 e). Also, I am not using charge equilibration from ReaxFF (using cheqeq no, and no fix qeq/reax command). Could anyone please guide me how to neutralize my system prior to ReaxMD in LAMMPS?
It won’t be a correct ReaxFF calculation without charge equilibration. The option to disable it is mostly for debugging purposes.
This has nothing to do with LAMMPS but general MD simulation knowledge. Obviously you need to add counterions. Which and how depend on the composition details of your system and how you obtained the initial charges. Placement of counterions can be trickly depending on the setup, since bad placement can result in unrealistic or unstable conditions or require extended equilibration time.