Abstract
Purchase PDF (258 K)
E-mail Article
Add to my Quick Links
Cited By in Scopus (2)
Purchase PDF (203 K)
doi:10.1016/j.cplett.2004.10.075 
Copyright © 2004 Elsevier B.V. All rights reserved.
Extraction of ionization energies from the ground-state two-particle reduced density matrix
References and further reading may be available for this article. To view references and further reading you must purchase this article.
Received 3 September 2004;
Abstract
Two methods for extracting ionization energies from the two-particle reduced density matrix (2-RDM) are explored: (i) diagonalization of the Hamiltonian in the basis of a single annihilation operator applied to the ground-state wave function |Ψg
and (ii) diagonalization of the Hamiltonian in the basis of two annihilation and one creation operators applied to the ground-state |Ψg. While the second basis set is more accurate, its Hamiltonian matrix elements depend upon the 3- and 4-RDMs. Using cumulant theory, however, we can approximate the 3- and 4-RDMs as functionals of the 2-RDM. Both methods are illustrated with calculations on a series of atoms and molecules.
