“…Information described can include properties such as molecular weight, geometry, volume, surface areas, ring content, rotatable bonds, interatomic distances, bond distances, atom types, planar and nonplanar systems, molecular walk counts, electronegativities, polarizabilities, symmetry, atom distribution, topological charge indices, functional group composition, aromaticity indices, solvation properties, and many others (Cramer et al, 1988;Randic, 1995;Schuur et al, 1996;Bravi et al, 1997;Hemmer et al, 1999;Pearlman and Smith, 1999;Hong et al, 2008;Roberto Todeschini, 2010). These descriptors are generated through knowledge-based, graph-theoretical methods, molecularmechanical, or quantum-mechanical tools (Acharya et al, 2011;Marrero-Ponce et al, 2012) and are classified according to the "dimensionality" of the chemical representation from which they are computed (Ekins et al, 2007): 1D, scalar physicochemical properties such as molecular weight; 2D, molecular constitution-derived descriptors; 2.5D, molecular configuration-derived descriptors; 3D, molecular conformation-derived descriptors. These different levels of complexity, however, are overlapping with the more complex descriptors, often incorporating information from the simpler ones.…”