A conceptual DFT study of the chemical reactivity of magnesium octaethylporphyrin (MgOEP) as predicted by the Minnesota family of density functionals

Abstract

The Minnesota family of density functionals has been assessed for the calculation of the molecular structure and electronic properties of a Mg(II)-porphyrin, namely Magnesium Octaethylporphyrin (MgOEP). Several global descriptors arising from Conceptual DFT have been calculated through a ΔSCF procedure, and by means of the HOMO and LUMO frontier orbitals. On the basis of the obtained Conceptual DFT indices, a series of descriptors have been devised in order to verify the fulfillment of the "Koopmans' theorem in DFT" procedure. It is shown that the density functionals that verify this approximation with a certain degree of accuracy are only those denoted as range-separated hybrids (RSH), while the usual GGA-hybrids and the local density functionals fail completely.