Theoretical study of the electronic structure of KLi molecule: Adiabatic and diabatic potential energy curves and dipole moments

Abstract

For all states dissociating below the ionic limit Li−K+, we perform an adiabatic and diabatic study for 1Σ+ electronic states dissociating into K (4s, 4p, 4d, 5s, 5p, 5d, 6s)+Li (2s, 2p, 3s). Furthermore, we present the adiabatic results for the 1–11 3Σ, 1–8 1,3Π and 1–4 1,3Δ states. The present calculations on the KLi molecule are complementary to previous theoretical work on this system, including recently observed electronic states that had not been calculated previously. The calculations rely on an ab initio pseudo-potential, Core Polarization Potential operators for the core–valence correlation and full valence CI approaches, combined to an efficient diabatization procedure. For the low-lying states, our spectroscopic constants and vibrational level spacing are in good agreement with the available experimental data. Diabatic potentials and permanent dipole moments are analyzed, revealing the strong imprint of the ionic state in the 1Σ+ adiabatic states.