Calculation of EPR g tensors for transition-metal complexes based on multiconfigurational perturbation theory (CASPT2)

Summary, in English

The computation of the electronic g tensor by two multireference methods is presented and applied to a selection of molecules including CN, BO, AIO, GaO, InO, ZnH, ZnF, O-2, H2O+, O-3(-), and H2CO+ (group A) as well as TiF3, CuCl42-, Cu(NH3)(4)(2+) and a series of d(1)-MOX4n- compounds, with M = V Cr, Mo, Tc, W, Re and X = F Cl, Br (group B). Two approaches are considered, namely, one in which spin-orbit coupling and the Zeeman effect are included using second-order perturbation theory and another one in which the Zeeman effect is added through first-order degenerate perturbation theory within the ground-state Kramers doublet. The two methods have been implemented into the MOLCAS quantum chemistry software package. The results obtained for the molecules in group A are in good agreement with experiment and with previously reported calculated g values. The results for the molecules in group B vary. While the g values for the d(1) systems are superior to previous theoretical results, those obtained for the d(9) systems are too large compared to the experimental values.

• Author: Steven Vancoillie; Per-Åke Malmqvist; Kristine Pierloot
• Department/s: Computational Chemistry
• Publishing year: 2007
• Language: English
• Pages: 1803-1815
• Publication/Series: ChemPhysChem
• Volume: 8
• Issue: 12
• Links: http://dx.doi.org/10.1002/cphc.200700128
• Document type: Journal article
• Publisher: John Wiley & Sons Inc.
• Topic: Theoretical Chemistry (including Computational Chemistry)
• Keywords: EPR; electronic structure; ab initio calculations; computer chemistry; transition metals; spectroscopy
• Status: Published
• ISBN/ISSN/Other: ISSN: 1439-7641