Total topological index

A total topological index x having a high discriminating power can also be derived as the following ... 

Another index in the topological state formalism has been developed. The total topological index t, has been defined, based on a summation of the topological state T, values. 

The average relative error is 3.9%, and no observation has a relative error greater than 10%. These results are significantly better than those given by the Hansch model. Hansch and Lien > found it necessary to delete two observations to achieve r - 0.911,5 = 0.22. When the full data set is used, the statistics are even worse r = 0.878, s = 0.24. The potential value of this total topological index x is yet to be explored. Because it is a very highly discriminating index, there may be a useful role for it in QSAR. 

The concept of topological state and the total topological index [381],... 

MDL QSAR MDL Information Systems, Inc. www.mdl.com/products/predictive/qsar/index.jsp Molecular property descriptors, total topological descriptors, E-state indices... 

Note that the total structure connectivity index is the square root of the - simple topological index proposed by Narumi for measuring molecular branching. 

A list of molecular identification numbers is given below. Other important ones are the Hosoya ID number, the -> hyper-Wiener index, the - restricted walk ID number, and the total topological state, defined elsewhere. 

The most well-known complexity indices are listed below. Other molecular descriptors which give information about molecular complexity are the indices of neighbourhood symmetry and the - total adjacency index. The latter was proposed by Bonchev and Polansky [Bonchev and Polansky, 1987] as a simple measure of topological complexity, being a measure of the degree of connectedness of molecular graph. 

As the diagonal entries are just the vertex degrees 6, the first term on the right is the - total adjacency index Ay The topological state index is one of the -> molecular ID numbers. 

Hosoya, H., Hosoi, K. and Gutman, I. (1975a). A Topological Index for the Total jt-Electron Energy. Proof of a Generalized Htickel Rule for an Arbitrary Network. Theor.Chim.Acta, 38, 37-47. 

Methods Using 2D and ID Descriptors A good number of articles on aqueous solubility used a nonlinear method of data analysis, in particular, for methods developed with ID and 2D descriptors. Huuskonen [16] used E-state indexes [52,53] and several other topological indexes, with a total of 30 indexes, to develop his models. The predicted results for the 413 test set, SE = 0.71, calculated with MLRA were improved with a neural network, resulting in SE = 0.6. Tetko [17] noticed that E-state indexes represent a complete system of descriptors for molecules, and thus only these descriptors are sufficient to develop the aqueous solubility model. Indeed the model developed by the authors using exclusively E-state indexes provides similar results when compared to the model of Huuskonen [16]. Later on, the model was redeveloped using the Associative Neural Network (ASNN) method [54],... 

Narumi harmonic topological index Narumi geometric topological index Total structure connectivity index Pogliani index Ramification index Polarity number... 

The total sum of the entries of the distance matrix is another topological index called Rouvray index (or rank distance or total vertex distance) and is denoted as Irouv> which is twice the Wiener index W ... 

Total topological state index based on electrotopological state indices Flexibility index kpi kp2/nvx)... 

---