The　geometrical/electronic　structures,　X-ray　photoelectron　spectroscopy　(XPS)　and　near-edge　X-ray　absorption　fine　structure　spectroscopy　of　two　especially　C74　fullerenes　(D3h–C74　and　C1–C74)　and　the　chlorinated　species　C1–C74Cl10,　which　are　newly　isolated　in　the　experiment,　have　been　calculated　by　means　of　the　density　functional　theory　(DFT)　method.　Effective　changes　in　the　electronic　structure　and　simulated　X-ray　spectra　have　been　observed　after　chlorination.　Strong　isomer　dependence　has　been　found　in　both　spectra,　thus　the　‘fingerprints’　in　the　spectra　can　be　employed　as　a　tool　to　identify　the　isomers.　The　ultraviolet-visible　(UV-vis)　absorption　spectrum　of　C1–C74Cl10　has　been　performed　by　using　the　time-dependent　DFT　method.　The　generated　UV-vis　spectrum　coincides　with　the　previous　experimental　counterpart.　The　results　of　this　work　can　provide　useful　information　especially　for　isomer　identification　and　further　study　on　fullerenes　by　means　of　the　aforementioned　spectroscopy　techniques.　©　2018　Informa　UK　Limited,　trading　as　Taylor　&　Francis　Group.