Graph spectral analysis of nonane isomers

A group of substances known as alkanes is made up of carbon and hydrogen atoms bound together only by single covalent bond with the chemical formula C$_n$H$_{2n+2}$. Isomers are those molecules with identical chemical formula but different structural arrangement. Due to this, their corresponding molecular graphs differ in structure thereby leading to distinct spectral parameters. In this work, the spectral parameters of all isomers of nonane C$_9$H$_{20}$ have been computed and its relationship with its eigenvalue-based entropy is established. The spectral results are then correlated with the density value of the nonane isomers and it is found that the “spectral gap” is closely associated to that of density.