Magnetostructural Dependencies in $3d^2$ Systems: The Trigonal Bipyramidal V$^{3+}$ Complex

TL;DR

This paper develops a multi-configurational theoretical approach to study magneto-structural correlations in $3d^2$ systems, validated on a trigonal bipyramidal V$^{3+}$ complex, showing good agreement with experimental data.

Contribution

It introduces a restricted active space self-consistent field method tailored for $3d^2$ systems, enabling accurate modeling of magneto-structural properties.

Findings

The method accurately reproduces experimental magnetization and susceptibility data.

Good agreement with cw-EPR and photoluminescence spectroscopy results.

The approach is applicable to a wide range of $3d^2$ magnetic systems.

Abstract

We introduce a multi-configurational approach to study the magneto-structural correlations in $3d^2$ systems. The theoretical framework represents a restricted active space self-consistent field method, with active space optimized to the number of all non-bonding orbitals. To demonstrate the validity and effectiveness of the method, we explore the physical properties of the trigonal bipyramidal spin-one single-ion magnet (C$_6$F$_5$)$_3$trenVCN$^t$Bu. The obtained theoretical results show a good agreement with the experimental data available in the literature. This includes measurements for the magnetization, low-field susceptibility, cw-EPR and photoluminescence spectroscopy. The proposed method may be reliably applied to a variety of $3d^2$ magnetic systems. To this end, and for the sake completeness, we provide detailed analytical and numerical representations for the generic Hamiltonian's effective matrix elements related to the crystal field, exchange, spin-orbit and Zeeman interactions.