[lammps-users] pair_lj96_cut

Dear all,

In order to implement a 30-6 Lennard-Jones pair potential (PRE 70,
061507), I compared pair_lj_cut.cpp and pair_lj96_cut.cpp.

* First I was wondering what was the difference between the two
methods to read the parameters:

The force->numeric() version is better. I'll look at the tail
correction for 96.


Hi, Laurent, I have checked it again, you are right. There is mistake
in the pressure tail.

Best wishes,


I agree that that 2 should be a 4. Thank you for pointing out the error. We're posting a patch.

I'll attach my derivation in case anyone wants to see it. I'll also attach a paper that shows the general tail correction equations (see eq 5).


9-6 tail corrections.pdf (22 KB)

COMPASS, An ab Initio Force-Field Optimized forCondensed-Phase Applications.pdf (275 KB)

Thank you for your answer.

By the way, if by chance anyone is interested in the 30-6 LJ
potential, I will be happy to share it.

It has been used to modify at short range the BKS potential
(describing silica) to avoid unphysical "fusion" events between Si and
O atoms at high temperatures:


Enclosed are the cpp and h files. I don't think it will be very useful
to lots of users, but otherwise I can prepare the related doc page.

Best regards,

pair_lj306_cut.cpp (20.1 KB)

pair_lj306_cut.h (1.52 KB)