Theoretical study of two Ih-symmetry-breaking C60 isomers and their chlorinated species in core-excited and ground states

► We examine the electronic structures of Ih-, C2v-, Cs-C60 and C60Cl8, C60Cl12. ► XPS and NEXAFS spectra of Ih-, C2v-, Cs-C60 and C60Cl8, C60Cl12 are also explored. ► Both the NEXAFS and XPS spectra show strong isomer dependence. ► C atoms at pentagon-pentagon/three-hexagon ring fusions exhibit peculiar signals. ► A large blue shift in both the NEXAFS and XPS spectra is observed after chlorination.