Dear lammps users and the author of lammps,
FENE potential in lammps includes two terms: the first term is the
attractive, the 2nd Lennard-Jones term is repulsive. The first term
extends to R0, the maximum extent of the bond. The 2nd term is
cutoff at 2^(1/6) sigma.
When modelling polymer system, I define FENE bond style, and provide the
coefficients of the style, and also use command “special_bonds 0.0 1.0 1.0”.
So for the bonded atoms the lj potential is calculated in lammps FENE
potential, which may be efficient, but I have a question: for the bonded monomers, lj
potential is cut at 2^(1/6) sigma, which is not always the general case in polymer
simulation. For example, if I want to cut lj potential between all monomers at
2.5 sigma, how should I do? There is a method, but I am not sure: only the
first attractive term in present FENE potential is needed, and then calculate lj
potential between all monomers via “special_bonds 1.0 1.0 1.0”. Is that right?