Recurrence spectra and closed orbits of He+2 in parallel electric and magnetic fields

By the semi-classical closed orbit theory and region-splitting consistent iteration method, we calculated the recurrence spectra and closed orbits of He+2 in parallel electric and magnetic fields. Using the new potential with electronic exchange interaction, complex channel quantum defects and molecular closed orbits theory, we discussed the influence of molecular core to the recurrence spectra and closed orbits.