[lammps-users] fiber-fiber intercation

Dear Lammps user,

How can I choose the pair styles in order to simulate the interaction between two nanofibers in distance S to each other?
Is the below specification for a united atom system is correct? I chose a large cutoff greater than distance S (S= distance between COM of fiber 1 and fiber 2)

pair_style lj/cut/coul/cut 15
bond_style harmonic
angle_style harmonic
dihedral_style multi/harmonic
improper_style harmonic
pair_modify mix geometric tail yes
special_bonds lj/coul 0 0 0.5

Schematic:
Screen Shot 2020-12-18 at 13.38.05.png

How can I choose the pair styles in order to simulate the interaction between two nanofibers in distance S to each other?
Is the below specification for a united atom system

This looks like a pair of cylinders.

is correct?
pair_style lj/cut/coul/cut 15
bond_style harmonic
angle_style harmonic
dihedral_style multi/harmonic
improper_style harmonic
pair_modify mix geometric tail yes
special_bonds lj/coul 0 0 0.5

Not enough information to say either way. I can at least say that I
don't see anything obviously wrong with these settings. (In other
words, the syntax of each command looks okay. I don't know if this
feedback is very helpful.)

I chose a large cutoff greater than distance S (S= distance between COM of fiber 1 and fiber 2)

This means that particles in the two fibers will (probably) exert a
force on each other. Depending on the Lennard-Jones parameters you
chose in the pair_coeff command, this interaction could be attractive
or repulsive. (Probably repulsive.) You need to look at the
documentation, and decide what kind of cutoff and Lennard-Jones
parameters are appropriate for this system:


If you are simulating polymers using a popular force field, then the
force field itself will determine the correct cutoff and lennard-jones
parameters to use for the atom types in your molecules. You need to
decide what force field is appropriate for the molecules you are
simulating. (Popular united-atom force fields are OPLSUA, GROMOS, and
TraPPE.) I would search for papers that are similar to the ones you
want to use, and see which force field they chose.

Cheers
Andrew