  Transferrins are proteins responsible for transporting metal ions in all
vertebrates. However, the iron binding properties of transferrins remain poorly
understood. Iron, as a transition metal, forms ions with partially-occupied 3d
subshells. The electrons within the 3d orbitals of iron-bound transferrin are
therefore highly localized, and interact with one another in a complex manner
that cannot be fully characterized by considering each electron separately. In
this work, we make use of dynamical mean field theory, a technique that
accounts for the strong interactions between these electrons. This is a higher
level of theory than has ever been used to study transferrins. We present novel
data on the effective spin, multiplet states and optical spectra of iron-bound
human serum transferrin.
