The spontaneous electron emission and rotational predissociation lifetimes of the diatomic silver anion

The process of a two-channel decay of the diatomic silver anion (Ag2-), namely the spontaneous electron ejection giving Ag2 + e- and the dissociation leading to Ag- + Ag is theoretically studied. The ground state potential energy curves (PECs) of the neutral silver dimer and anionic silver diatomic molecule are calculated using the single reference coupled-cluster method with singles and doubles, and perturbative triples (CCSD(T)). The proper pseudopotential and optimized basis set are used in the presented approach. The interaction energies are corrected for the basis set superposition error (BSSE) by counterpoise (CP) correction. Based on the energies of rovibrational levels calculated using PECs, we are able to characterize the decay channels and compare our results with the experimental data. Having the ground state PEC of an anionic system, we calculate the quantum dynamics (QD) of the dissociation process, which allows us to calculate the widths and lifetimes of highly-lying rovibrational levels. The predissociation lifetimes for quasibond states with small widths of levels are treated with a time-independent approach. We also present the non-adiabatic coupling matrix element between chosen initial and final vibrational states of Ag2- and Ag2, which allow us to estimate the spontaneous electron emission lifetimes.