Hi everyone
The wB97X functional in Psi4 appears to be have the wrong parameters.
The range-separation omega parameter should 0.3 according to the original paper but is 0.4 in the code and in the manual. And energies differ compared to wB97X in other codes.
The wB97 functional is fine. I have not checked the others wB97-type functionals.
Changing the parameter in psi4/share/psi4/python/procedures/functional.py gives energies that agree with other codes.
Cheers, Ragnar