Abstract
We discussed how the orbital ambiguity in general SCF theory can be removed to obtain the orbital set which is stable to an excitation. The orbital ambiguity for the ground state wavefunction can be resolved while at the same time performing the configuration interaction calculation for the specific singly excited states. That is, the orbitals can be uniquely determined so that they have the physical significance that they satisfy particular types of the Brillouin conditions for the excited states considered in addition to the Brillouin theorem for the ground state. This implies that the definition of Huzinaga's potential to obtain meaningful virtual orbitals is generalized to include wavefunction for open‐shell systems.