Modelling Properties of Molecules with open d- or f-Shells Using Density Functional Theory

Abstract

A new, non-empirical, Density Functional Theory (DFT) based Ligand Field (LF) model is proposed. The calculation involves two steps: (i) an Average Of Configuration (AOC), with equal occupation of the d- or f-orbitals is carried out, (ii) with these orbitals kept frozen, the energies of all Single Determinants (SD) within the whole LF manifold is performed. These energies are then used to estimate all the Racah- and LF-parameters needed in a conventional LF calculation. The results of this first-principle prediction are in very good agreement with the experimental values. Sample calculations of tetrahedral and octahedral Cr-complexes, hexa-acquo Ni(II)-and octaacquo Gd(III)-complexes are used to validate the new model and to analyse the calculated parameters.