Dear Lammps users,
Is it possible to have a A and B style LJ potential added in the LAMMPS package? I am using a forcefield with direct A and B (negative). My programming ability is not enough to implement it in the source code. If you experts can implement it in the Lammps, this pair style would be a really helpful function.
The two different representations can usually be converted from one to the other.
For cases that cannot, you can still use pair style table or consider lennard/mdf ( https://docs.lammps.org/pair_mdf.html )
automatic mixing requires a representation in (or conversion to) epsilon/sigma format as the mixing rules apply to epsilon and sigma, not A and B.
thus any other implementation of an A-B style Lennard-Jones potential cannot not have automatic mixing either.
if you have only a tiny distance between inner and outer cutoff for the tapering function there should be no significant difference. besides, if the cutoff is so small that the tapering function makes a significant difference, then you introduce a significant error into your simulation anyway.
Thanks Axel. I am aware of the lennard/mdf and table method. However, they are not as powerful as the epsilon and sigma method. They need to mix manually and lennard/mdf is with a tapering function. I’ll try them first to see the results.
Thank you, Axel. I’ll try it.