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Updated: Feb 19, 2026
Hyperspectral Imaging as a Tool to Study Optical Anisotropy in Lanthanide-Based Molecular Single Crystals
Published on: April 14, 2020
Fast and reliable ab initio calculation of crystal field splittings in lanthanide complexes
P P Hallmen1, C Köppl2, G Rauhut2
1Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
Abstract:
Ab initio calculations of crystal field splittings and magnetic properties of lanthanide complexes are usually performed using state-averaged complete active space self-consistent field (CASSCF) calculations and a subsequent spin-orbit calculation mixing the CASSCF wave functions (CASSCF/state interaction with spin-orbit coupling). Because this approach becomes very time-consuming for large molecules, simplifications have been proposed in the literature to determine the state-averaged orbitals by configuration-averaged Hartree-Fock (CAHF) instead of CASSCF. We present an approach which is an extension of the CAHF method. We combine the techniques of local density fitting with CAHF and achieve a significant speedup compared to CASSCF without loss in accuracy. To assess the performance of our method, we apply it to three well-known molecules, namely, Er[N(SiMe3)2]3, Er(trensal), and the double-decker (NBu4)+ [Er(Pc)2]-.
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