“…Of the 476 chemicals in the original data set, seven were two-atom compounds and thus not included in the present study due to the fact that the triplet indices, which are described in the following section, cannot be calculated for two-atom compounds. The molecular weights of the compounds in this data set range from 40 to 338, and the chemical diversity is described in Table 1 23 The topological descriptors include Wiener number, 24 molecular connectivity indices developed by Randić 25 and Kier and Hall, 26 frequency of path lengths of varying size, 26 information theoretic indices defined on distance matrices of graphs using the methods of Bonchev and Trinajstić, 27 Roy et al, 28 as well as those of Raychaudhury et al, 33 parameters defined on the neighborhood complexity of vertices in hydrogen-filled molecular graphs, 29-33 a simple hydrogen bonding parameter, 23 and Balaban's J indices 34 as well as the triplet indices. 35,36 The triplets result from a matrix, main diagonal column vector, and free term column vector which are converted into a system of linear equations.…”