Free atom 4f photoelectron spectra of Au, Pb, and Bi

High resolution 4f photoelectron spectra have been measured from Au, Pb, and Bi vapors using synchrotron radiation. New accurate binding energy values are found to deviate more than 0.3 eV for Au from the previous results demonstrating the need for new precise values, e.g. for chemical shift and cluster studies. For Bi both atomic and diatomic lines have been observed simultaneously, molecular lines at 0.96 eV lower binding energies. Fine structure splitting created by the coupling of the 4f core hole to the open 6p shell has been found to manifest itself in this high resolution experiment as slightly different line widths for 4f spin components. The fine structure has been investigated also theoretically by calculating the 4f photoionization energies, intensities, and lifetimes using the multiconfigurational Dirac-Fock approach.