Comparison of the saddle-point method and the Feshbach-type projection method

Journal Article · Thu Nov 01 04:00:00 EST 1990 · Physical Review, A; (USA)

DOI:https://doi.org/10.1103/PhysRevA.42.5726· OSTI ID:5836729

Chung, K T ^[1]

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1. Department of Physics, North Carolina State University, Raleigh, NC (USA) Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan, (Republic of China)

In this work, we compare the saddle-point method with the Feshbach-type projection-operator method using experimental and theoretical data in the literature. It appears that the saddle-point energy gives a better approximation to the resonance energy. This result is explained in terms of the variational principle of quantum mechanics. It is also pointed out that the existing Feshbach-type projection method is not suitable for general triply excited states such as (2{ital snln}{prime}{ital l}{prime}) where {ital n},{ital n}{prime}{ge}3.

• OSTI ID: 5836729
• Journal Information: Physical Review, A; (USA), Journal Name: Physical Review, A; (USA) Vol. 42:9; ISSN 1050-2947; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
CALCULATION METHODS
COMPARATIVE EVALUATIONS
DATA ANALYSIS
ELECTRONIC STRUCTURE
ELEMENTS
FLUIDS
GASES
HELIUM
MATHEMATICAL OPERATORS
NONMETALS
PROJECTION OPERATORS
RARE GASES
RESONANCE
SADDLE-POINT METHOD