Response to lsquo;lsquo;Comment on lsquo;The exactness of the extended Koopmansrsquo; theorem: A numerical studyrsquo;rsquo; lsqb;J. Chem. Phys.99, 6221 (1993)rsqb;

摘要

The exactness of the extended Koopmansrsquo; theorem (EKT) has been studied by performing extensive multiconfiguration Hartreendash;Fock and configuration interaction calculations on excited states of Be and Be+. The results show that the EKT ionization potential for the Be(1S) to Be+(2P) ionization is not equal to the energy difference between the cation and the neutral atom. For Be(3P), two of the EKT ionization potential values approach, in the limit of a complete basis, the values of the ionization potentials obtained as the appropriate energy difference.