Perspective: Björn Roos and direct configuration interaction

Autor: Isaiah Shavitt
Rok vydání: 2010
Předmět:
Zdroj: International Journal of Quantum Chemistry. 111:3263-3266
ISSN: 0020-7608
DOI: 10.1002/qua.22949
Popis: The introduction, impact, and development of the direct configuration interaction (CI) approach are reviewed. The removal of the limitation on the size of CI calculation by eliminating the need to store the Hamiltonian matrix and the streamlining of the calculation of the eigenvector updates in each iteration are seen to be the key transformative contributions of this approach. The initial introduction, limited to closed-shell single-reference CISD (CI with single and double excitations) calculations, underwent successive generalizations, culminating in procedures based on the graphical unitary group approach, allowing applications to multireference CISD calculations for any electronic state. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem 111:3263–3266, 2010
Databáze: OpenAIRE