Ab initio studies of tetracyanoethylene-based organic magnets

Abstract

We study electronic and geometric structures of a single tetracyanoethylene (TCNE) and metal–TCNE clusters that constitute a transition metal ion (Mn,V) and an organic molecule in the presence of solvent, CH 2Cl 2, via density functional theory (DFT) methods. For TCNE, the particular attention is given to its π → π * transition, when the molecule is in - 1 valence state. Electronic levels of the molecule obtained from DFT calculations are compared with those obtained from Huckel methods. In the case of metal–TCNE clusters, energetics of magnetic interaction between a metal ion and the organic molecule, electronic structure, onsite Coulomb energies and binding energies are calculated.