Problem on the torsion term in "airebo potential" and confused it with torsion part in Rebo term

Dear lammps users,

  1. Actually, I 'm doing the of-plane bending for the monolayer graphene. I found that when I turn on the torsion term, the bending stiffness decreases compare with the case of turning off the torsion term. It seems the decreased bending stiffness is contrary to the theory analysis, as the additional torsion term increases the bending potential. I’m wrong or right?

  2. When I check the torsion term from the reference”A reactive potential for hydrocarbons with intermolecular interactions ”, I confused it with torsion part in Rebo term, could you please explain the difference between them?

  3. Besides, Could I say the “2nd generation REBO potential” is “2nd generation Brenner potential”?

Thanks a lot in advance!

The first paragraph of the pair airebo doc page explains what literature
versions of REBO and AIREBO the LAMMPS implementation corresponds to.
The torsion term in the code is also documented with the formulas from
the papers. So I suggest the answer to your first Q is in the papers, not
in the LAMMPS implementation.