Applicability of self-consistent field techniques based on the complex coordinate method to metastable electronic states

Abstract

Hartree–Fock theory is applied to resonance states of an atomic Hamiltonian under the complex coordinate transformation. It is concluded that for shape resonances restricted Hartree–Fock theory provides a useful and practical approach to the problem of computing the complex resonance energy. Numerical results are presented for the low-energy 2P shape resonance in e–Be scattering. With properly chosen basis functions the resonance energy obtained in these calculations is practically independent of the phase of the complex scaling parameter for a wide range of values. Application of this technique to molecular resonances is discussed. The widths of Feshbach resonances cannot be obtained from the theory in its present form, but it is suggested that a complex coordinate form of multiconfiguration self-consistent field theory may be appropriate for that case.