Sorry please rephrase your question first.

Syful Akash

It depends on what kind of MD simulation you want to perform. Sometimes for a material (like NaCl) we have different potential models. Each potential can simulate some physical properties with good accuracy and other not. For example, if you are simulating mechanical properties of NaCl crystal you have to use one potential model and when you are simulating NaCl solubility in water "maybe" you have to use another potential model.

Then:

1- Study about the problem you want to solve, and see what kind of NaCl properties are important in your case.

2- Read papers about MD simulation of NaCl and see which one focuses on similar issue like yours. Then you can also use that potential.

Thanks Amir Reza Ansari Dezfoli Sir, actually I want to make NaCl salt structure by Na and Cl. In this case which interaction potential should I use in LAMMPS?

Dear Syful Akash

I suggest you use: The potentials of mean force (PMFs) or embedded ion method (EIM) potential.

Please see this page: https://lammps.sandia.gov/doc/pair_eim.html

Here I make you a In_file for crystalline NaCl LAMMPS, Enjoy it!!

Just download LAMMPS and run it. That is all you have to do!

# if run long enough (e.g. 1M steps), the unstable CsCl form of a NaCl single # crystal can be annealed to the correct NaCl type of NaCl polycrystals units metal atom_style atomic read_data data.eim pair_style eim pair_coeff * * Na Cl ffield.eim Na Cl neighbor 0.3 bin neigh_modify delay 0 every 1 timestep 0.0005 thermo_style custom step pe pxx pyy pzz temp velocity all create 1400.0 43454 dist gaussian mom yes fix int all npt temp 1400.0 1400.0 0.1 aniso 0.0 0.0 0.1 # anneal in much longer run #fix int all npt temp 1400.0 300.0 0.1 aniso 0.0 0.0 0.1 run 100

Dear Amir Reza Ansari Dezfoli Sir,

Thanks a lot. This was very helpful. If you suggest me about some material to study MD that will be helpful for me.