Conceptual density functional theory CDFT

However, the quest for the theoretical basis of the hard soft acid base behaviour has created such a surge of fundamental research in chemistry that it gave birth of a new branch of density functional based theoretical science known as Conceptual Density Functional Theory, CDFT (Geerlings et al. 2003). 

The conceptual density functional theory has added Maximum Hardness Principle, (MHP) (Pearson 1987) and Minimum Polarizability Principle, (MPP) (Chattaraj and Sengupta 1996) to the list of the fundamental laws of nature. The CDFT has been successfully exploited in elucidating and correlating mechanistic aspects viz. regio-selectivity, catalysis, aromaticity, intramolecualr rotation, inversion and isomerization reactions (Zhou and Parr 1989 Parr and Chattaraj 1991 Chattaraj et al. 1994 Pearson and PaUce 1992 Pal et al. 1993 Chattaraj et al. 1995 Ayers and Parr 2000 Ghosh et al. 2000, 2002). 

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