Defining charge, multiciplity for fragments in FI-SAPT0 calculations

Hi everyone,

Recently I realized an excellent analysis with the FI-SAPT0 on python. The system was: cation (monomer A)/p-R-phenyl(monomer B)-aromatic(monomer C). Total carge=+1, Total multiciplity=1, Fragment charges +1, 0, 0 and fragment multiplicities 2, 2, 1. Both A and B monomers separated by sigma bonds from the aromatic monomer C (A-C-B). A and B interacts via H-bonds through an interaction cation-pi. The calculations were great with para-phenyl R=H,F,CH3 but when I after put R=cianide, methoxy or hydroxy the modulus failed mentioning a bad definition in multiplicity. I tried defining the fragment charge and multiplicity in many ways, renumbering atoms and changing the the parameters defined from Arrays. Nothing resulted. I don’t know if the inductive effect on p-R-phenyl is the problem maybe, Could someone help me pleas? Many thanks :pray: