Correlation effects in the electronic structure of theMn4molecular magnet

Abstract

We present joint theoretical-experimental study of correlation effects in the electronic structure of ${(\mathrm{py}\mathrm{H})}_{3}[{\mathrm{Mn}}_{4}{\mathrm{O}}_{3}{\mathrm{Cl}}_{7}{(\mathrm{O}\mathrm{Ac})}_{3}]\ensuremath{\cdot}2\mathrm{Me}\mathrm{C}\mathrm{N}$ molecular magnet $({\mathrm{Mn}}_{4})$. Describing the many-body effects by cluster dynamical mean-field theory, we find that ${\mathrm{Mn}}_{4}$ is predominantly a Hubbard insulator with strong electron correlations. The calculated electron gap $(1.8\phantom{\rule{0.3em}{0ex}}\mathrm{eV})$ agrees well with the results of optical conductivity measurements, while other methods, which neglect many-body effects or treat them in a simplified manner, do not provide such an agreement. Strong electron correlations in ${\mathrm{Mn}}_{4}$ may have important implications for possible future applications.