[lammps-users] Modifying LJ potential

Dear Lammps users,

I would like to modify the LJ potential as following

U = 4e ((s/r)^12 - c*(s/r)^6).

I haven’t done any coding in C++. Which files should I be modifying in order to make this potential work.


Hi Dhondi,

I think you don't need to change the code. If your potential is
U = 4e ((s/r)^12 - c*(s/r)^6) you can convert it to LAMMPS LJ potential if
you set e=E/c^2 and s=S*c^1/6.

U = 4E/c^2((S*c^(1/6)/r)^12 - c*(S*c^(1/6)/r)^6)
U = 4E/c^2(c^2*(S/r)^12-c^2*(S/r)^6)
U= 4E((S/r)^12 - (S/r)^6) which is the LJ cut form of LAMMPS

(Please check the algebra, I am quite rusty at this )

Another option is to use pair_style table instead of changing LAMMPS code.