I am running a calculation to evaluate the intermolecular energies of various systems using the following call:
E_mp2_tz= psi4.energy(‘mp2/cc-pvtz’, bsse_type = ‘cp’, molecule=mol)
When I assign bsse_type as cp, I get a much lower energy output in hartrees relative to when this is removed from the calculation. I have assumed this value corresponds to the energy output of the system relative to zero hartrees since when I convert this output to kcal/mol I get reasonable values for the intermolecular energies. Therefore, when I see a negative value that should mean my intermolecular system should attract at the given output energy while a positive should mean the system is repulsive at the given energy.
I would appreciate your feedback on whether this assumption is unwarranted.