This is probably not the kind of response that you are hoping to get, but please note that even though you are aiming to use LAMMPS in your simulations, what you are asking about are not questions pertinent to LAMMPS but rather about your research and specifically force field parameterization. That is very different from helping people with how to use LAMMPS, and thus your question is off-topic for this forum. I could re-categorize it to the Science Talk category, but I doubt that you will get much help there either. In fact, I doubt that you will find the level of support and assistance you are looking for in any online forum. What you are asking about is something that you need to discuss with domain experts and if you don’t have those available to talk to in person directly, will likely have to find a suitable collaborator and can provide the desired expertise and guidance.
To understand better what you can or cannot get from this forum, I suggest you have a good look at this post: Please Read This First: Guidelines and Suggestions for posting LAMMPS questions