Messages

I looked at the potential energy formula in the RASPA manual and found that I need to modify the FEYNMAN_HIBBS_LENNARD_JONES formula into a higher order form to better use it for the correction inside the molecule, but I can't find the place to define this formula expression in the RASPA source package, can you provide me some guidance?

The force field used in my simulation is the dreiding force field. Different from the traditional LJ potential, the hydrogen and deuterium molecules I simulated will involve quantum effects, and the LJ parameters after quantum correction should be used (the parameters I selected are those proposed by darkrin and Levesque in Monte Carlo simulations of hydrogen absorption in single walled carbon nanotubes), and the Feynman Hibbs fourth effective potential should be used for simulation, But when building the force field file, I'm not sure if I'm right to use Feynman Hibbs quartic effective potential. After consulting all the documents about Feynman Hibbs effective potential, there is no specific method to add this potential energy to the simulation file, so I put the force field mixing rules in the force field file according to some statements Def in this file, the potential energy name of the molecule I want to simulate is changed from LJ potential to FH quartic effective potential. Do you know if this is correct? The following is my force field mixing rules For the parameters of hydrogen and deuterium gas I defined in the def file, the first column is energy, the second column is distance, and the third row is the correction factor of quantum correction in my simulation. I don't know whether it is directly added here. Is it added here or corrected?
H_com   FEYNMAN HIBBS LENNARD JONES      36.7     2.958   1.008
D_com   FEYNMAN HIBBS LENNARD JONES      36.7   2.958 2.016
H_h2   Lennard-jones   0.0   0.0
D_d2   Lennard-iones   0.0   0.0