Parr and Pearson and founded on the energy parameters exclusively. The efforts to find another source of the atomic hardness parameters have long history. 68,69, The problem has been analyzed in depth by Ayers; the old relations between the size and polarizability and softness/hardness have been reminded and many more arguments have been raised, leading to the conclusion that the original concept I-A might be reconsidered. A solution has been proposed in the following papers by Cardenas et al. who introduced the benchmark values of the chemical hardness for atoms. These values are also based on the energy parameters exclusively, nevertheless, they represent most reasonable set of data to which our results might be compared. This has been demonstrated in Fig. in the (Z) relationship that shows the asymptotic behavior of the index. While the actual data may differ in details, the trends in both series of data are reasonably parallel, thus opening a chance to investigate the next derivative in the row.