Special bonds for custom table potential

LAMMPS LAMMPS General Discussion
1

Hi all,

I am simulating a polymer using harmonic bonds and a custom table pair potential (not lj).

################################
## Between bonded atoms
################################

bond_style   harmonic
special_bonds lj 0 1 1
bond_coeff   *   30.0   1.0


################################
## Between non-bonded atoms
################################

pair_style	hybrid/overlay table linear 2000000
pair_coeff	* * table soft.table soft_core_lj 1.35
pair_modify     tabinner 0.0000000001 shift yes
pair_write 	1 1 10000 r 0.01 1.35 soft_sim.txt LJ

Everything works fine. I am confused about “special_bonds lj”, what is lj refering to here? If I have understood the documentation correctly, it should switch of custom table potential between 1-2 while keeping pair table potential fully between 1-3 and 1-4.

Do I need something like “pair_modify special lj 0.0 1.0 1.0” ?

Requesting clarification.

2

All pairwise interactions that are not Coulomb pair styles.

No. But it would have no effect, anyway.

You can do that for yourself by setting up systems with very few atoms and specific bonding patterns where you can compute the interactions yourself by hand and then compare to what LAMMPS is doing.