[narvaezwilberth]

Are the molecular orbitals computed by Gaussian09 required to be orthogonal to each other?

I am attempting to compute a pseudo-potential, so I require my core MOs to be orthogonal to my valence MO. I have tested the orthogonality between the core MOs and valence MO, and found that they are neither orthogonal to one another nor normalized.

Can the result possibly be correct?