Electron-topological matrix of congruity

Figure 3.47. The electron-topological matrix of congruity (ETMC) for a 17-atom fragment proposed by Bersuker and Dimoglo (455) to encode geometrical and electronic features of molecules.

For each molecule with A atoms, the square symmetric Ax A matrix, called the electron-topological matrix of congruity ETMC, is defined as the following ... 

Given a series of N molecules with known biological activity or inactivity and provided that the conformations and electronic structure of these molecules can be determined, the essence of the ET method is as follows.For each molecule the so-called electron-topological matrix of congruity (ETMC) or, in the more sophisticated versions, a set of ETMC —the three-dimensional ETMC (TDETMC) —is constructed as shown schematically below. 

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