Electronic structure and rovibrational predissociation of the 2sPi state in KLi

TL;DR

This study calculates potential energy curves for KLi's excited states, analyzes rovibrational predissociation, and accurately models the dissociation process, matching experimental spectra and predicting unassigned spectral lines.

Contribution

The paper provides detailed potential energy curves and a time-dependent analysis of rovibrational predissociation in KLi, including predictions of unassigned spectral lines.

Findings

Good agreement between calculated and experimental spectra

Identification of a small dissociation barrier supporting quasi-bound states

Successful prediction of previously unassigned spectral lines

Abstract

Adiabatic potential energy curves of the 3sSigma+, 3tSigma+, 2sPi and 2tPi states correlating for large internuclear distance with the K(4s) + Li(2p) atomic asymptote were calculated. Very good agreement between the calculated and the experimental curve of the 2sPi state allowed for a reliable description of the dissociation process through a small (20 cm-1 for J = 0) potential energy barrier. The barrier supports several rovibrational quasi-bound states and explicit time evolution of these states via the time-dependent nuclear Schroedinger equation, showed that the state populations decay exponentially in time. We were able to precisely describe the time-dependent dissociation process of several rovibrational levels and found that our calculated spectrum match very well with the assigned experimental spectrum. Moreover, our approach is able to predict the positions of previously unassigned lines despite their low intensity