Dear LAMMPS users and developers,
I’m currently working on molecular dynamics of molecular solids. I’ve been looking for a force field suitable for my system. I found a formalism by Anthony Stone (The theory of intermolecular forces(2013) and Chem. phys. lett. 145.5 (1988): 365-370.), which is rooted on the use of spherical harmonics to describe the potential surfaces around the molecules. I looked for similar potentials in LAMMPS documentation but could not find it. Are you aware if something like this have been implemented?
If it is not mentioned in the manual, the LAMMPS developers are usually not aware of it.
There are (literally) several hundreds of forks of the LAMMPS repository on GitHub and we cannot keep track of them. On top of that, there are plenty of people doing modifications to LAMMPS that are not in a public repository. Since LAMMPS is designed to make it easy to customize it, there is no way to follow this and we are dependent on people submitting their code for inclusion into the distribution (a large part of LAMMPS is the result of such contributions).
The closest to what you describe would be the SNAP package in LAMMPS, but it is likely too different to be of immediate use to you.
I am currently out of the office right now so I can’t give a very detailed response, but just as a passing glance you may want to look at the compute orientorder/atom command. I remember some conversation about spherical harmonics on the mailing list long ago. You may want to give the archives a dig.