The linear response kernel of conceptual DFT as a measure of aromaticity.

We continue a series of papers in which the chemical importance of the linear response kernel χ(r,r') of conceptual DFT is investigated. In previous contributions (J. Chem.

Molecular Orbital-Averaged Fukui Function for the Reactivity Description of Alkaline Earth Metal Oxide Clusters.

This paper concerns the accurate description of the surface oxygen reactivity for the alkaline earth metal oxides using local DFT-based reactivity indices. The cumbersome periodic boundary conditions calculations, typically required to probe the reactivity of such systems, are avoided by the construction of a reliable cluster model. The standard Fukui function concept of conceptual DFT is generalized to include the contribution from not only the HOMO and the LUMO but also from other chemically relevant orbitals.

Calculation of Fukui Functions Without Differentiating to the Number of Electrons. 3. Local Fukui Function and Dual Descriptor.

An alternative approach for the calculation of DFT-based reactivity descriptors involving derivatives of the energy with respect to the number of electrons and the external potential is further evaluated. Using functional derivatives with respect to the external potential, the finite difference approximation was avoided for the local calculation of the Fukui functions and the dual descriptor. A relevant set of molecules has been calculated after the optimization of computational parameters.

On the position of the potential wall in DFT temporary anion calculations.

A simple method was recently proposed [D. J. Tozer and F.

Computing Fukui functions without differentiating with respect to electron number. II. Calculation of condensed molecular Fukui functions.

The Fukui function is a frequently used DFT concept in the description of a system's regioselective preferences to undergo electrophilic, nucleophilic, or radical attacks. Until now, this function has usually been evaluated using finite difference approximations. The first paper in this series proposed a method for obtaining the Fukui function by a direct calculation of the functional derivative of the chemical potential with respect to the external potential.

Calculation of negative electron affinity and aqueous anion hardness using kohn-Sham HOMO and LUMO energies.

An important chemical property emerging from density-functional theory is the hardness, which can be evaluated as half of the difference between the vertical ionisation energy and electron affinity of the system. For many gas phase molecules, however, the electron affinity is negative and standard ways of evaluating this property are troublesome. In this contribution, we investigate an unconventional approximation for the electron affinity, based on the Kohn-Sham orbital energies of the frontier orbitals and the ionisation potential.