The restricted active space (RAS) state interaction approach with spin-orbit coupling

Per-Åke Malmqvist, Björn Roos, B Schimmelpfennig

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727 Citations (SciVal)


A method to compute spin-orbit coupling between electronic states is presented. An effective one-electron spin-orbit Hamiltonian is used, based on atomic mean field integrals, The basic electronic states are obtained using the restricted active space (RAS) SCF method. The Hamiltonian matrix is obtained by an extension of the restricted active space state interaction (RASSI) method. Several hundred states can be included. Tests for atoms and molecules from the entire periodic system show accurate results. Computed spin-orbit effects on relative energies are normally accurate within a few percent. The method has been included in the MOLCAS-5.0 quantum chemistry software. (C) 2002 Elsevier Science B.V. All rights reserved.
Original languageEnglish
Pages (from-to)230-240
JournalChemical Physics Letters
Issue number3-4
Publication statusPublished - 2002

Bibliographical note

The information about affiliations in this record was updated in December 2015.
The record was previously connected to the following departments: Theoretical Chemistry (S) (011001039)

Subject classification (UKÄ)

  • Theoretical Chemistry


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