On physical analysis of free Gibb's energy based on topological indices for nickel sulfide

Nickel sulfides are inorganic compounds of chalcogens and transition metals with formula of NiS_x, where nickel is from 10th group and sulfur is from 16th group of periodic table. Topological indices play a key role in analyzing and understanding the topology of chemical compounds. In the chemical structure of any compound, atoms are considered as vertices, while the bounds between these atoms are edges. The purpose of this paper is to analyses the structure of nickel (II) sulfide. Moreover, we have computed the topological indices of molecular structure of nickel (II) sulfide. The regression models between the standard molar free Gibb's energy, specific heat and each topological index of nickel (II) sulfide for different formula units have been developed. The basic purpose of these regression models is to develop a relationship between free Gibb's energy GE, specific heat C_p and topological indices of nickel (II) sulfide. More preciously, we provided a new direction in this field of research to analysis the physio-chemical properties like Gibb's energy using the concept of chemical graph theory.