according to the documentation:
“An alternative slab option can be invoked with the nozforce keyword in lieu of the volfactor. This turns off all kspace forces in the z direction.”
I am wondering if there’s any reference for the choice of kspace_modify with slab nozforce, instead of using a value of volfactor, say 3.0, as usually done in the literature.
I don’t think there is a reference, but I recall a discussion on this mailing list about that subject and if I remember correctly, that prompted the implementation of the flag. So digging through the mailing list archives might provide an answer, why this was needed and what it was used for.
Stan might have a citation.
I believe the original purpose of “slab nozforce” was to couple to another code/package that provided this force instead of LAMMPS KSpace. Like USER-ATC or something like that, I don’t recall 100%.