Ab initio study of the electronic structures of lithium containing diatomic molecules and ions

Abstract

Ab initio calculations are used to provide bond lengths, harmonic frequencies, and dissociation energies of low‐lying electronic states for LiX, LiX+, and LiX− (with X=Li through F and Na through Cl). Most of these species represent hitherto experimentally unknown molecules or ions, which provides the focus of the work presented here. All of these species are stable to dissociation and the anions are stable to loss of an electron. Differences among the electronic structures of the valence isoelectronic LiX; and HX, LiX+, and HX+; and LiX− and HX− species are analyzed. Optimized geometries, dissociation energies,ionization potentials, and electron affinities were calculated for the following ground states of the respective species: 1Σ+ for Li2(1Σ+ g ) LiNa, LiBe+, LiBe−, LiMg+, LiMg−, LiF, LiAl, LiS−, and LiCl; 2Σ+ for Li+ 2(2Σ+ g ), Li− 2(2Σ+ u ) LiBe, LiB+, LiF−, LiNa+, LiNa−, LiMg, LiAl+, and LiCl−; 2Π r for LiB−, LiAl−; 2Π i for LiO, LiF+, LiS, and LiCl+; 3Π r for LiB, LiC+, and LiSi+; 3Σ− for LiN, LiO+, LiSi−, LiP, and LiS+; 4Σ− for LiC, LiN+, LiN−, LiSi, LiP+, and LiP−; and 5Σ− for LiC−.