Pair_style for A,B version of lj-12/6 potential

LAMMPS LAMMPS Mailing List Mirror
1

Dear Developers and Users

I’m working on a paper in which LJ parameters are provided as A, B in compliance with the expression: E=A/r12 - B/r6.

However, for an atom type, the B parameter is zero!

I’ve already searched the manual and I found that all lj pair styles are in terms of epsilon and sigma. However, in my case, I cannot derive any corresponding parameters having zero B.

Does anybody know a proper action to do? I don’t find suitable pair_style Is it my fault or the shortcoming of lammps?

Besides, in case of exiting another pair style, it would be truly problematic since hybrid potential could not be handled by GPU. Why developers did not make formulation based on A and B parameters.

Axel or Steve may have some explanation.

2

The formula for an LJ potential is in terms of epsilon and sigma. I.e.

A and B in your formula are not independent if you want a LJ potential.

If you want a polynomial potential with arbitrary A,B, then you’d have to

create your own pair style. Or tabulate it and use pair_style table.

If you do that, you can use whatever A,B values you want, including 0.0.

Steve