Calculation of exchange energies using algebraic perturbation theory
- Mathematics Section Faculty of Computing, Engineering and Technology Staffordshire University, Beaconside, Stafford ST18 0DG (United Kingdom)
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138 (United States)
- Department of Physical Chemistry, Hebrew University of Jerusalem, Jerusalem IL-91904 (Israel)
An algebraic perturbation theory is presented for efficient calculations of localized states and hence of exchange energies, which are the differences between low-lying states of the valence electron of a molecule, formed by the collision of an ion Y{sup +} with an atom X. For the case of a homonuclear molecule these are the gerade and ungerade states and the exchange energy is an exponentially decreasing function of the internuclear distance. For such homonuclear systems the theory is used in conjunction with the Herring-Holstein technique to give accurate exchange energies for a range of intermolecular separations R. Since the perturbation parameter is essentially 1/R, this method is suitable for large R. In particular, exchange energies are calculated for X{sub 2}{sup +} systems, where X is H, Li, Na, K, Rb, or Cs.
- OSTI ID:
- 21408597
- Journal Information:
- Physical Review. A, Vol. 81, Issue 4; Other Information: DOI: 10.1103/PhysRevA.81.042508; (c) 2010 The American Physical Society; ISSN 1050-2947
- Country of Publication:
- United States
- Language:
- English
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