[lammps-users] Multiple Pair Potentials


In my previous e-mail, I should have said “buck,” not buck/coul/cut. I believe you end up double-counting the short-range interactions if you use lj/cut/coul/long with buck/coul/cut or buck/coul/long.

Sorry if this caused any confusion.


I have put together my simulation and defined all my interaction parameters as below. I am just wanting to check whether the interaction parameters which I am trying to model, is actually what I have done within LAMMPS.

Atoms 1-5 - Fluid
Atoms 6,7 - Surface

Interactions wanted:
1-7 - Coulombic interaction - All atoms
1-7 - LJ interaction, excluding surface-surface interactions, but including surface-fluid interactions
6,7 - Buckingham interaction between surface atoms.

For the LJ, I have defined the 1-1, 2-2, … interaction parameters. Will the 1-2, 1-3 parameters automatically be calculated using mixing rules using the pair_styles that I have chosen or will I have to define these explicitly? Are all my other interaction correctly defined?


I think you want to use hybrid/overlay rather than hybrid. Otherwise, I think the Buckingham potential coefficients will overwrite the corresponding LJ potential lines, and it’s not clear that you’d have the electrostatics for types 6 and 7 in the short-range terms.