DSF-Potential curve

Dear LAMMPS-users,

i tried to investigate some interactions in my water-submerged system by plotting potential curves for some isolated pairs of atoms, using lj/cut/coul/dsf.

The reason being that the lj and coulomb interactions seem to be not in the right proportion in my md simulation.

I noticed that the coulomb-energy is always shifted, even when plotting the interaction of a charged with an uncharged atom.

Furthermore, the shift seems kind of random.

I’m aware that the formalism is not intended for isolated atoms, but this still worries me.

Please find attached the plots for different pairs of atoms.

Can anyone tell me if this is to expected, and if there is a better way to verify my setup?

Thanks in advance,


Further information:

units real


CC 0

OS -0.427

OW -0.83

HW 0.415

axes: x/Å, y/kcal


The author of the potential is listed at the top of the source

file. Trung is now at Northwestern U. You can send him an