Bk Approximation Applied to the Multireference Configuration Interaction Method

Vladimír Sychrovský, Petr Čársky, Hans Lischka

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


The single-reference configuration interaction through quadrupoles CI SDTQ-Bk method has been extended to the general multireference CI method in the Bk approximation (MR CI-Bk). The computer code is based on the traditional graphical unitary group approach (GUGA)-CI technique, and it processes only the loops (coupling coefficients) that are necessary for the MR CI-Bk Hamiltonian matrix evaluation. The number of processed loops, and therefore also the cost of calculation, is considerably lower than in the case of the respective complete MR CI calculation. The method was tested on the ground-state potential curves of the N2, F2, and HF molecules, by comparing the calculated MR CI-Bk energies with the available literature data obtained by complete MR CI and full CI calculations.

Original languageEnglish
Pages (from-to)185-196
Number of pages12
JournalInternational Journal of Quantum Chemistry
Issue number2
StatePublished - Jan 15 2000


  • Configuration interaction
  • Correlation energy
  • N, F, and HF potential curves
  • Quadruply excited configuations
  • Size consistency


Dive into the research topics of 'Bk Approximation Applied to the Multireference Configuration Interaction Method'. Together they form a unique fingerprint.

Cite this