Algebraic relationships between conceptual DFT quantities and the electronegativity equalization hardness matrix

An alternative method for the calculation of conceptual Density Functional Theory (DFT) quantities from the hardness matrix in the electronegativity equalization method (EEM) is presented. This approach not only allows the speed-up of EEM calculations, but also reveal interesting new relationships between the hardness matrix and atomic charges, Fukui functions, atom condensed softness and molecular electronegativity, hardness and softness.