Introduction to the electronic structure, luminescence, and magnetism of lanthanides

Abstract

This introductory chapter describes theoretical tools and methods employed for the description of the optical and magnetic properties of lanthanide compounds. First, we introduce the electronic structure of the free lanthanide ions in gas phase, a multiplet structure with an overview of the effect of the ligand (crystal) environment on the low-lying multiplets. Second, crystal and ligand field theories applied in this field are briefly introduced together with their grounds and drawbacks. The foundations of the Judd-Ofelt theory describing the intensities of the optical transitions in lanthanide compounds are discussed. Recent advances in the ab initio theoretical methods used for the description of lanthanide complexes are introduced. Further, theoretical requirements for top-performant molecular magnets are reviewed alongside a brief review of the recent top-performant molecular magnets obtained experimentally. Finally, a personal opinion regarding the future (theoretical) work that needs to be done in this area is given.