Global similarity approach

Full structure search can be developed by using similar approaches to those employed in the case of 2D structure search. Thus, some topological indices can be modified in such a way that they include geometrical information. For example, the global index given by Eq. (4) can be modified to Eq. (11), where are real interatomic distances. 

A theoretical foundation of molecular similarity analysis is the assumption of neighborhood behavior ,which refers to the tendency of molecules with globally similar structures to exhibit similar biological activity. The well-known similarity-property principle (SPP) of Johnson and Maggiora expresses this paradigm and promotes a holistic view of molecular structure and properties. Molecular similarity applications assume that chemical similarity can be related to biological activity in a meaningful manner. However, the success of this approach ultimately depends on the way molecular similarity is defined. 

Based on a similar approach to that used to define - WHIM descriptors, G-WHIM descriptors [Todeschini et al, 1997a Todeschini and Gramatica, 1998] are global molecular descriptors of - molecular interaction fields. 

Several kinetic models regarding the reduction of NO with NH3 have been reported in the Uteratme for various catalyst technologies Tronconi et al. [29] and Chatteijee et al. [30] for Vanadia-based catalysts, Malmberg et al. [21] and Schuler et al. [31] for Fe-zeolite catalysts and Olsson et al. [32] for Cu-zeohte catalysts. Neglecting detailed kinetic mechanisms and reaction intermediates, which are beyond the scope of this chapter, a similar global modeling approach can be used for the common SCR catalytic materials. The major reactions, considered in this model, are given below. 

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