Chemical Information from Information Discrimination and Relative Complexity

Abstract

Following the spirit of the Hohenberg-Kohn theorems of DFT, the atomic and molecular density functions are used as the key parameters to extract chemical information. The functional form of the Kullback-Leibler relative information measure permitted the construction of density functionals, which along with the choice of a good reference density, for example, noble gas elements, is shown to reveal the periodicity in Mendeleev’s table. Similarly, the specific choice of the transition state as reference, leads to valuable information on the chemically interesting reaction profiles. The investigation of atomic complexity measures is reported in terms of the non-relativistic and relativistic shape electron densities. Such an analysis leads to the interesting result that the atomic complexity derived from the relativistic electron density increases with atomic number whereas a saturation value is attained when the non-relativistic density is employed. It is shown that a relative complexity measure can be defined which reflects the diversity of electron density functions with respect to a reference atom as the sub shells are filled across the periodic table.