Experimental observation of relativistic effects on electronic wavefunction for iodine lone-pair orbital of CF3I

The binding energy spectra of CF3I in the energy range 9–15 eV have been measured by a newly developed high resolution (e, 2e) spectrometer with 0.5 eV energy resolution. The two spin-orbit splitting components 5e3/2 and 5e1/2 of iodine lone-pair orbital have been partially resolved and their individual electron momentum distributions have been obtained, together with their branching ratio as a function of momentum. The experimental results show the obvious relativistic effects on the wavefunctions for 5e3/2 and 5e1/2 orbitals.