Online ISSN: 1097-461X    Print ISSN: 0020-7608
International Journal of Quantum Chemistry
Volume 82, Issue 5, 2001. Pages: 255-261

Published Online: 9 Apr 2001

Copyright © 2001 John Wiley & Sons, Inc.


 Properties, Dynamics, and Electronic Structure of Atoms and Molecules
Resonance states of atomic anions
Alexei V. Sergeev *, Sabre Kais
Department of Chemistry, Purdue University, 1393 Brown Building, West Lafayette, Indiana 47907
email: Alexei V. Sergeev (kais@power1.chem.purdue.edu)

*Correspondence to Alexei V. Sergeev, Department of Chemistry, Purdue University, 1393 Brown Building, West Lafayette, Indiana 47907

Funded by:
 Office of Naval Research; Grant Number: N00014-97-1-0192
 NSF Early-Career Award

Keywords
resonance states; negative ions; complex rotation method; screened Coulomb potential; ionization energy

Abstract
We study destabilization of an atom in its ground state with decrease of its nuclear charge. By analytic continuation from bound to resonance states, we obtain complex energies of unstable atomic anions with nuclear charge that is less than the minimum critical charge necessary to bind N electrons. We use an extrapolating scheme with a simple model potential for the electron, which is loosely bound outside the atomic core. Results for O2- and S2- are in good agreement with earlier estimates. Alternatively, we use the Hylleraas basis variational technique with three complex nonlinear parameters to find accurately the energy of two-electron atoms as the nuclear charge decreases. Results are used to check the less accurate one-electron model. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 82: 255-261, 2001


Received: 11 April 2000; Revised: 29 January 2001; Accepted: 1 February 2001