Predissociation resonances and accurate ab initio calculations of dication HF2+

It is very interesting and challenging to investigate the electronic structures of diatomic dications, due to the nature of coulombic repulsive and bound attractive dissociation limits and their avoided diabatic interactions. Using the multi-reference configuration interaction approach, comprehensive ab initio calculations of the first 36 electronic states, corresponding to 15 dissociation limits, of dication HF2+ are reported. Good agreements for the vertical excitation energies and dissociation limits are achieved with the available references. Besides the common interesting quantities as adiabatic potential energy curves, dipole moments and spectral constants for the bound states, the nonadiabatic radial coupling matrix elements for the (1,3)pi states are also presented. A showcase for the diabatic potentials of (3)pi states are presented and discussed. Furthermore, predissociation states from the nonadiabatic couplings or avoided crossing of potential energy curves, known as shape resonances in collisions, are also investigated by using the WKB and scattering methods.

Automated summary

This study investigates the electronic structures of diatomic dications, specifically focusing on dication HF2+, achieving good agreement with available references. In addition to common physical quantities, nonadiabatic radial coupling and diabatic potentials are presented. Further examination of predissociation states and shape resonances in collisions is conducted using WKB and scattering methods.