Methods and Models of Theoretical Calculation for Single-Molecule Magnets

Qian-Cheng Luo,Yan-Zhen Zheng

doi:10.3390/magnetochemistry7080107

Qian-Cheng Luo, Yan-Zhen Zheng

Open Access

https://doi.org/10.3390/magnetochemistry7080107

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Abstract

Theoretical calculation plays an important role in the emerging field of single-molecule magnets (SMMs). It can not only explain experimental phenomena but also provide synthetic guidance. This review focuses on discussing the computational methods that have been used in this field in recent years. The most common and effective method is the complete active space self-consistent field (CASSCF) approach, which predicts mononuclear SMM property very well. For bi- and multi-nuclear SMMs, magnetic exchange needs to be considered, and the exchange coupling constants can be obtained by Monte Carlo (MC) simulation, ab initio calculation via the POLY_ANISO program and density functional theory combined with a broken-symmetry (DFT-BS) approach. Further application for these calculation methods to design high performance SMMs is also discussed.

Highlights

Many excellent single-molecule magnets have been reported, After of effort, excellent single-molecule magnets have been reported, which hasyears depended on themany joint efforts of synthetic chemists and theoretical researchers
The commonly used static magnetic calculation methods are ab initio and density functional theory combined with the broken symmetry (DFT-BS)
ORCA and Molcas are commonly employed software packages. The former is used more in transition metallic systems, while the latter is used for rare-earth single-molecule magnets (SMMs)

Summary

Introduction

With the advent of the big data era, the capacity of information storage is in high demand. The main theoretical calculation methods used for molecular magnets are density functional theory (DFT) and ab initio calculation methods For the latter, the complete active space self-consistent field (CASSCF) method is widely adopted in the prediction of static magnetic properties for SMMs. the development of related software packages promotes the prediction of SMM properties and the understanding of magnetic relaxation processes. Charbotaru and Ungur et al developed two software packages, ORCA and Molcas, respectively, which have been successfully and widely used in the study of SMMs [21,22] Their output g values, crystal field parameters, transition magnetic moment matrix and susceptibility and magnetization curves are significant information to understand the magnetic relaxation process of SMMs. Especially the POLY_ANISO [23] program, based on the Lines model, which can realize the fitting of the magnetic interactions between the metal centers of bi- or multi-nuclear systems. We summarize the common calculation methods and models of mono-, biand poly-nuclear systems of SMMs, respectively, and explain the guiding role of theoretical calculation in synthetic chemistry by combining it with the practical work of our research group

Mononuclear Single-Molecule Magnets

Bi- and Multi-Nuclear Single-Molecule Magnets

Simple

17. The coupling models twohigh-nuclearity high-nuclearity copper copper cage

Conclusions and Perspectives