The electrotopological state is a new approach to defining key structural features of a molecule in drug design. Combining both electronic and topological attributes, the E-State index facilitates the development of a structure - activity model, the definition of a pharmacophore, and the search through a database for similar or dissimilar compounds.

The background for the method, the concept of the intrinsic state, and the E-State index as a function of the atom or group within the field of all atoms in a molecule are all described in this primer for a new structure paradigm. Software on the bundled CD-ROM allows the reader to compute and display the E-State indices for molecules, while examples in the book illustrate strategies that can be used in drug research.