The schultz index, modified schultz index and geometric arithmetic index, theoretical bond length and bond angle of chemical trees of Pentane isomers

Many organic molecules have a graph representation that is tree. Isomers have same chemical formula but different molecular structure. To determine how two chemical structures are different. In this paper we study a Hausdorff (H) distance, Geometrical – Arithmetic index (GA (G)), Schultz index (S_c* (G)), modified Schultz index (S_c)*) and Schultz polynomial, Modified Schultz polynomial for tress of pentane (C₅H₁₂) and its isomers, isopentane and neopentane, having three different tree graphs (chemical trees). We use Gaussian 0.3 computational chemistry software to interpretate the physical properties of these isomers. The bond length and bond angle are important characteristics of covalent bonding in molecules. The concept of bond length and bond angle permits us to get an immediate insight into the bonding situation in different molecules. The thermodynamic properties show that the intermolecular interactions become weaker as the molecular shape becomes more nearly spherical and the surface area decreases with branching.