The Tail-Correction in RASPA

[fjoodaki]

Hi!

I tried to use the tail-correction in RASPA. I found that the tail-correction portion of total energy is very high for low loading. I checked the RASPA source code. I found that when we turn on the tail-correction on RASPA, RASPA calculates the host-host tail-correction and adds it up to the host-guest and guest-guest tail correction portion.
Since, in adsorption problems, we are not interested in the host-host interactions, I was wondering why does RASPA calculate the tail-correction for the host-host interactions?

Thank you in advance for your guidance.

Best Regards,
Faramarz

[David Dubbeldam]

It would be inconsistent if the host-host contribution would be ignore. The large value is because you have a lot of VDW pairs in the framework.
Note: if a particle moves from A to B, in the energy difference that value cancels out. So it has little influence on adsorption, only via the positions of the framework atoms.

[fjoodaki]

Thank you very much for your answer, and sorry for my late response. I just saw your message.

For the adsorption process in a rigid framework, we are interested in potential energy of host-guest and guest-guest interactions; however, RASPA adds tail-correction potential of host-host interaction the total potential energy. I am using the total potential energy for an specif calculations so I have a concern about that host-host tail correction interaction.

Best Regards,
Faramarz