  We address the effect of functionalization on the electronic and magnetic
properties of magnetite surface as an indicator of the same properties in
nanoparticles too big for a direct ab-initio approach. Using well-established
methods and references (namely LDA+U on magnetite surfaces) we could verify the
validity of our approach, and using two typical ligands, dopamine and citrate,
namely pi and sigma electron donors, we could predict that those ligands would
induce a different change in the electronic properties of the systems, but in
both cases an enhancement of magnetization.
