The QB program: Analysing resonances using R-matrix theory

✍ Scribed by Lisa Quigley; Keith Berrington; John Pelan

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 710 KB
• Volume: 114
• Category: Article
• ISSN: 0010-4655
• DOI: 10.1016/s0010-4655(98)00059-9

✦ Synopsis

A procedure for analysing resonances in atomic and molecular collision theory is programmed, which exploits the analytic properties of R-matrix theory to obtain the energy derivative of the reactance (K) matrix. This procedure is based on the QB method (J. Phys. B 29 (1996) 4529) which defines matrices Q and B in terms of asymptotic solutions, the R-matrix and energy derivatives, such that dK/dE = B-IQ, from which eigenphase gradients of the K matrix can be obtained. Resonance positions are defined at the points of maximum gradient; resonance widths are related to the inverse of the eigenphase gradients; resonance identifications are estimated from outer region solutions. The program is tested on the twenty lowest Be-like Ne resonances ls22p1/2.3/2nl J = 1 ° (n < 10). The test data is incorporated in the Fortran program, which can therefore be compiled and run as it stands; otherwise the program is designed for input of an 'H-file' in the format defined by RMATRX1 (Comput. Phys. Commun. 92 (1995) 290). (~) 1998 Published by Elsevier Science B.V.