Calculations of cross sections for symmetric charge transfer of gadolinium and neodymium

The symmetric charge transfer reaction between the same kind of atoms and ions is the resonance charge transfer reaction without the transfer from atom energy to kinetic energy. Its reaction cross section is nearly inversely proportional to the ionizing potential of atoms, and its energy dependence is shown. There is only 10% of difference between the ionizing potential of gadolinium and neodymium, but the cross section of neodymium is about twice as large as that of gadolinium, and the energy dependences are also different. The reason of the large difference in cross sections is due to the electron state of transition metals. In this study, by taking gadolinium and neodymium as examples, the charge transfer cross sections were calculated taking the existence of d or f shell which are not closed shells into account, and were compared with the measured values. As for the symmetric charge transfer cross sections of gadolinium and neodymium when the atoms and ions are at ground state, the possible reaction paths, the method of calculation and the results are reported. in the comparison with the measured values, the measured values were 1.5 times as large as the calculated values, but the energy dependence and the difference between gadolinium and neodymium of the cross sections agreed well. (K.I.)