Effect of exohedral functionalization on the magnetic properties in the dysprosium-containing endohedral fullerene DySc2N@C80(CF2)

We present a quantum-chemical study of the effect of exohedral functionalization with a CF2 group on the lowest electronic states and the zero-field splitting pattern in a potential single-molecule magnet (SMM) compound DySc2N@C80(CF2). Multiconfiguration perturbational methodology is applied to various spin states of the endohedral compound, comparing different active spaces and state-averaging schemes in order to check for the possible involvement of orbitals other than 4f-Dy in the nondynamical electronic correlation and to suggest the most appropriate computational parameters. Combining the spin-orbit coupling calculations with perturbational corrections, we demonstrate that the interactions within the endohedral cluster and with the fullerene cage exert only a small effect on the non-relativistic approximation to the electronic states of the Dy3+ ion, yet they are significant enough to alter the picture of zero-field splitting depending on the orientation of the DySc2N cluster inside the fullerene cage.