DFT calculation of the intermolecular exchange interaction in the magnetic Mn$_4$ dimer

TL;DR

This paper uses density-functional theory to calculate the intermolecular exchange interactions in a Mn4 dimer, explaining its unique magnetic phenomena and aligning well with experimental results.

Contribution

It provides a detailed DFT-based analysis of the electronic structure and magnetic interactions in a Mn4 dimer, highlighting the role of antiferromagnetic exchange.

Findings

Good agreement with experimental magnetic data

Identification of strong antiferromagnetic exchange interactions

Explanation of quantum tunneling phenomena

Abstract

The dimeric form of the single-molecule magnet [Mn$_4$O$_3$Cl$_4$(O$_2$CEt)$_3$(py)$_3$]$_2$ recently revealed interesting phenomena: no quantum tunneling at zero field and tunneling before magnetic field reversal. This is attributed to substantial antiferromagnetic exchange interaction between different monomers. The intermolecular exchange interaction, electronic structure and magnetic properties of this molecular magnet are calculated using density-functional theory within generalized-gradient approximation. Calculations are in good agreement with experiment.