Chemical applicability of Gourava and hyper-Gourava indices

Topological indices are extensively used as molecular descriptors in building Quantitative Structure-Activity Relationship (QSAR), Quantitative Structure-Property Relationship (QSPR) and Quantitative Structure-Toxicity Relationship (QSTR). In this paper, Gourava and hyper-Gourava indices are tested with physico-chemical properties of octane isomers such as entropy, acentric factor and DHVAP using linear regression models. The first Gourava index highly correlates with entropy (coefficient of correlation 0.9644924) and the second Gourava index highly correlates with acentric factor (coefficient of correlation 0.962243). Further, Gourava and hyper-Gourava indices are obtained for the line graph of subdivision graph of 2D-lattice, nanotube and nanotorus of $TUC_4C_8[p,q]$.