Predicting some physicochemical properties of octane isomers: A\n topological approach using ev-degree and ve-degree Zagreb indices

Topological indices have important role in theoretical chemistry for QSPR\nresearches. Among the all topological indices the Randi\\'c and the Zagreb\nindices have been used more considerably than any other topological indices in\nchemical and mathematical literature. Most of the topological indices as in the\nRandi\\'c and the Zagreb indices are based on the degrees of the vertices of a\nconnected graph. Recently novel two degree concepts have been defined in graph\ntheory; ev-degrees and ve-degrees. In this study we define ev-degree Zagreb\nindex, ve-degree Zagreb indices and ve-degree Randi\\'c index by using these new\ngraph invariants as parallel to their corresponding classical degree versions.\nWe compare these new group ev-degree and ve-degree indices with the other\nwell-known and most used topological indices in literature such as; Wiener,\nZagreb and Randi\\'c indices by modelling some physicochemical properties of\noctane isomers. We show that the ev-degree Zagreb index, the ve-degree Zagreb\nand the ve-degree Randi\\'c indices give better correlation than Wiener, Zagreb\nand Randi\\'c indices to predict the some specific physicochemical properties of\noctanes. We investigate the relations between the second Zagreb index and\nev-degree and ve-degree Zagreb indices and some mathematical properties of\nev-degree and ve-degree Zagreb indices. Keywords:\n