A Cost-Effective Semi-Ab Initio Approach to Model Relaxation in Rare-Earth Single-Molecule Magnets

We discuss a cost-effective approach to understand magnetic relaxation in thenew generation of rare-earth single-molecule magnets. It combines ab initio calculations of thecrystal field parameters, of the magneto-elastic coupling with local modes, and of the phonondensity of states with fitting of only three microscopic parameters. Although much lessdemanding than a fully ab initio approach, the method gives important physical insights intothe origin of the observed relaxation. By applying it to high-anisotropy compounds with verydifferent relaxation, we demonstrate the power of the approach and pinpoint ingredients forimproving the performance of single-molecule magnets.