Improved algorithms for renormalized electron propagator calculations

✍ Scribed by V. G. Zakrzewski; O. Dolgounitcheva; J. V. Ortiz

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 161 KB
• Volume: 75
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/(sici)1097-461x(1999)75:4/5<607::aid-qua26>3.0.co;2-x

✦ Synopsis

A new algorithm has been developed for renormalized electron propagator methods that are appropriate for shakeup final states such as the algebraic diagrammatic construction in third order, the two-particle, one-hole Tamm᎐Dancoff approximation and the nondiagonal, renormalized, second-order approximation. All contractions are performed with transformed electron repulsion integrals that are stored on disk. It is formulated for closed-shell ground states and employs spin and point-group symmetry. Contributions from transformed integrals with four virtual indices may be computed by a direct algorithm, where integrals in the atomic basis are recalculated as needed. A representative application to the ionization energies of trans-1,3-butadiene is discussed.