For the first time, theoretical dependences of the width Г(eV) of the X-ray photoelectron spectra of the outer (OVMO) and inner (IVMO) valence molecular orbitals electrons without taking into account the An 6s electrons, as well as the intensities ratio of these spectra (I/I = OVMO/IVMO) calculated by the relativistic discrete variation method for AnO (An = Th–Lr) have been obtained depending on the atomic number Z. Satisfactory agreement has been established with the available relevant experimental data for AnO of light actinides. The decrease in the OVMO XPS width in the Pa–Lr series is associated with a shift in the partial density of states of the An 5 electrons to the OVMO bottom while the increase in the IVMO width is mainly due to an increase in the magnitude of the spin-orbit splitting (ΔE) of the An 6-electrons. It has been found that the OVMO intensity is mainly related to the An 5- and 6-electrons, since the photoionization cross sections for these electrons are significantly larger than those for the An 7-, 7-, and O 2-electrons.
Teterin et al. (Wed,) studied this question.