Abstract:

As evidenced from recent literature, interest in employing information theory measures for understanding different properties of atomic and molecular systems is increasing tremendously. Following our earlier efforts in this field, we here evaluate the feasibility of using information theory functionals such as Fisher information, Shannon entropy, Onicescu information energy, and Ghosh-Berkowitz-Parr entropy as measures of steric effects for the steric analysis of water nanoclusters. Taking the structural isomers of water hexamers as working models and using information theoretic quantities, we show that the relative energies of water nanoclusters and the computed steric energies are related. We also show the strong effects of steric repulsion on conformational stabilities. At the same time, we have also assessed the usefulness of simultaneously considering the different information theoretic quantities, and achieved more accurate descriptions of the stability of water nanoclusters. In order to consider the effects of cluster size on the obtained results and the extent of applicability of information theoretic quantities, we have also benchmarked larger water nanoclusters with 32 and 64 units. Scrutinizing the obtained data from information theory functionals, we found that Fisher information shows the best overall performance. Our findings underline that the information theoretic quantities, especially Fisher information, can be used as quantitative measures of relative energies and consequently the order of stability of nanoclusters, which affirmed the utility of information theory for investigating various physical and chemical problems.

Key words: Information theory, Fisher information, Shannon entropy, Onicescu information energy, Ghosh-Berkowitz-Parr entropy, Water nanocluster, Steric effect