Accurate crystal field Hamiltonians of single-ion magnets at mean-field cost

2025/05/22 by Linqing Peng, Peng, Linqing, Shuanglong Liu +10 · 1 citation
Materials Science · Chemistry · #Magnetism in coordination complexes #Organic and Molecular Conductors Research #Advanced NMR Techniques and Applications

paper · pdf · doi:10.48550/arxiv.2505.16905

Abstract

The effective crystal field Hamiltonian provides the key description of the electronic properties of single-ion magnets, but obtaining its parameters from ab initio computation is challenging. We introduce a simple approach to derive the effective crystal field Hamiltonian through density functional calculations of randomly rotated mean-field states within the low-energy manifold. In benchmarks on five lanthanide-based complexes, we find that we compute with mean-field cost an effective crystal field Hamiltonian that matches the state-of-the-art from much more expensive multi-configurational quantum chemistry methods. In addition, we are able to reproduce the experimental low-energy spectrum and magnetic properties with an accuracy exceeding prior attempts. Due to its low cost, our approach provides a crucial ingredient in the computational design of single-ion magnets with tailored physical properties and low-energy spectra.

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Cited by

• Phase Space Electronic Structure Theory: From Diatomic Lambda-Doubling to Macroscopic Einstein-de Haas

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