A new determinant-based full configuration interaction method
Abstract
Siegbahn recently presented a new direct Cl method which is applicable to the CAS SCF method. Instead of using configuration state functions as adopted by Siegbahn, we propose that Slater determinants should be used. The approach then needs no formula tape, the one-electron coupling coefficients being easily generated as required. The method is totally vectorised, and applies as programmed to the lowest eigenvalue of any spin and space symmetry. The timings for Siegbahn's examples are appropoximately halved using this procedure, and in a full CI calculation involving 107942 configurations, 18 CRAY-1S CPU seconds were required per iteration.
- Publication:
-
Chemical Physics Letters
- Pub Date:
- November 1984
- DOI:
- 10.1016/0009-2614(84)85513-X
- Bibcode:
- 1984CPL...111..315K