A full multichannel iteration formalism using the Schwinger variational principle

Journal Article · Sat May 01 04:00:00 EDT 1993 · Bulletin of the American Physical Society

OSTI ID:281552

Goforth, T L; Watson, D K

We have developed a full formalism for the Schwinger Variational Principle. A complete variational wavefunction matrix is obtained using the multichannel Lippman-Schwinger equation. Each element of this matrix contains a wavefunction describing the scattering process which connects one initial state of the system to one final state. The elements of the Schwinger K matrix are then individually improved through iteration by using the appropriate wavefunction matrix elements to improve the basis set. This approach removes the dependence of the final results on the choice of initial basis set and provides a mans of systematically converging the multichannel K matrix. We have also investigated a computationally simpler approximation which uses only the first raw of the wavefunction matrix. This approximation allows the use of a single set of channel basis sets for all of the elements of the K matrix and significantly reduces the complexity of the calculations and the computer time required to obtain convergence. Both the full formalism and the approximate method have been tested on the e-H system.

• OSTI ID: 281552
• Report Number(s): CONF-9305421--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 3 Vol. 38; ISSN BAPSA6; ISSN 0003-0503
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ELECTRON-ATOM COLLISIONS
HYDROGEN
LIPPMANN-SCHWINGER EQUATION
VARIATIONAL METHODS
WAVE FUNCTIONS