Jensen-Tsallis divergence and atomic dissimilarity for position and momentum space electron densities.

Quantifying the dissimilarity among two or more many-electron systems by means of their one-particle densities is a hot topic within the physical applications of the information theory. This is a relevant achievement of the so-called "divergence measures," for which several definitions have been considered, each one with its own advantages and difficulties. Nevertheless, all of them are considered in order to disclose the differences among the involved systems, neutral atoms in the present work, according to their densities in the position and momentum spaces. The pioneering Jensen-Shannon divergence (JSD) constitutes a particular case of the one-parameter Jensen-Tsallis divergence (JTD). The analysis here provided for the JTD of atomic systems generalizes and improves some previous results on the JSD one. Such an improvement mainly arises from the capability of JTD to modify, by means of its characteristic parameter, the relative contribution of relevant specific regions of the atomic densities in both conjugated spaces.