How can i set the range of coulomb interaction ( ex)2.5 Angstrom ~ 10Angstrom )

LAMMPS LAMMPS General Discussion
1

Dear LAMMPS users and developers,

I’m currently trying to describe the Tersoff potential and the Coulomb interaction together.
I know that I can use both pairs styles together through hybrid/overlay, but what I want to know is to specify the minimum distance that the Coulomb interaction applies.

For example, I want to apply the Coulomb interaction only when the distance between atoms is greater than 2.5 angstroms while applying the Tersoff potential for all atoms.

I kept looking for the LAMMPS command, but I couldn’t find the minimum distance to exclude that potential.

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I would be really grateful if I could get your help.
Thanks.

2

There is no such coulomb pair style in LAMMPS. You will have to implement it yourself.

I doubt that just turning coulomb on at 2.5 Angstrom will be a good model, since you will have a sudden and very significant jump in forces and energy which can cause all kinds of bad things (bad energy conservation, instabilities, undesired geometries). There is plenty of literature on how important it is to have energies and forces that are continuous.