Dear colleagues,

Sorry in advance, but I ended up with a very simple question. I just want to confirm that I understand correctly what I read in the Lammps manual.

Suppose I fitted an energy curve for angle bending term from quantum mechanics data and the expression I got was:

In the Lammps manual for the “quartic angle style”, it is described that a factor of 1/2 is included in K. Due to the parameters I obtained when adjusting the curve, I would have to use K1 = 50, K2 = -100 and K = 150, correct?

Another possibility would be to use the “class2 angle style” (with M and N = 0). However, in this case (as it is not explicitly stated) I would not consider a factor of 1/2 in K. So I would normally use K1 = 100, K2 = -200 and K = 300, correct?

Thanks for a while.

Best regards,

**Emerson Parazzi Lyra**

PhD candidate

School of Chemical Engineering

University of Campinas

500 Albert Einstein Ave, Campinas, SP, 13083-852, Brazil

Email: [email protected]

Orcid ID: https://orcid.org/0000-0002-7969-3764