Applications of the Schwinger multichannel method to electron-molecule collisions

Journal Article · Mon Jan 01 04:00:00 EST 1990 · Physical Review, A (General Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevA.41.327· OSTI ID:6981982

Lima, M A.P.; Brescansin, L M; da Silva, A J.R. ^[1]; Winstead, C; McKoy, V ^[2]

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1. Instituto de Fisica Gleb Wataghin, Unicamp, Caixa Postal 6165, 13081 Campinas, Sao Paulo (Brazil)
2. Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125 (USA)

We discuss some recent developments in the implementation of the Schwinger multichannel method for electron-molecule collision calculations. The evaluation of matrix elements involving the operator {ital VG}{sub {ital P}}{sup (+)}V, previously accomplished by insertion of a Gaussian basis on either side of {ital G}{sub {ital P}}{sup (+)}, is now done by direct numerical quadrature. This approach avoids the necessity of very large Gaussian basis sets, allowing the size of the basis to reflect only the dynamical requirements of the scattering wave function. We find that the reduction in the required basis size results in improved efficiency, in spite of the additional numerical effort of performing the quadrature. Trial applications to electron-CH{sub 4} scattering in the static-exchange approximation and to electronic excitation of H{sub 2} illustrate the excellent convergence characteristics of the procedure.

• OSTI ID: 6981982
• Journal Information: Physical Review, A (General Physics); (USA), Journal Name: Physical Review, A (General Physics); (USA) Vol. 41:1; ISSN PLRAA; ISSN 0556-2791
• Country of Publication: United States
• Language: English

Related Subjects

640304* -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
74 ATOMIC AND MOLECULAR PHYSICS
ALKANES
COLLISIONS
ELASTIC SCATTERING
ELECTRON COLLISIONS
ELECTRON-MOLECULE COLLISIONS
ELEMENTS
ENERGY-LEVEL TRANSITIONS
EQUATIONS
EXCITATION
FUNCTIONS
HAMILTONIANS
HYDROCARBONS
HYDROGEN
INTEGRAL EQUATIONS
LIPPMANN-SCHWINGER EQUATION
MATHEMATICAL OPERATORS
METHANE
MOLECULE COLLISIONS
NONMETALS
ORGANIC COMPOUNDS
QUANTUM OPERATORS
SCATTERING
SERIES EXPANSION
WAVE FUNCTIONS