Capping C72 through C6: studying the relative stability of the five C78 fullerene isomers

The penultimate step of the circumscribe algorithm proposed on Graph Theoretical footings is analyzed by an involved quantum–chemical AM1 method. The five C72 isomers generated through the different base excised internal structures are subjected to a relative stability study. Finally a relationship between the C72 isomers with their corresponding five C78 (IPR) fullerenes has been used to establish a relative stability trend. The most unstable C72 isomer is found to generate the most stable C78 (IPR) isomer through the capping technique used in the circumscribing algorithm. Further, the least spherical isomer attains the most spherical geometry after capping.