Excited Li and Na in Hen: Influence of the dimer potential energy curves

Abstract

The X(2)Σ ground and the A(2)Π and B(2)Σ first two excited states of Li-He and Na-He are determined using high level complete active space self-consistent field-multireference configuration interaction ab initio method. The obtained potentials differ from the ones proposed by Pascale [Phys. Rev. A 28, 632 (1983)], more strongly for the ground than for the excited states. Quantum diffusion Monte Carlo studies of small Li(∗)He(n) and Na(∗)He(n) with n ≤ 5 are performed using a diatomics-in-molecule approach to model the non-pair additive interaction potential. The sensitivity of our results to the A(2)Π and B(2)Σ potentials used is assessed by an analysis of the structure and of the energetics of the clusters. For these small clusters, the physical conclusions are essentially independent of the diatomic curves employed.

Theoretical profiles of the Mg+resonance lines perturbed by collisions with He

“…Also, the Russel-Saunders spin-orbit coupling in the ion Mg + (∆ SO = 91.57 cm −1 ) is comparable to that of the Na atom (∆ SO = 17.20 cm −1 ) (Dell'Angelo et al 2012;Allard et al 2014b), but still roughly five times larger. However, we make the hypothesis that the effect of the value of the atomic Mg + spin-orbit coupling parameter ∆ SO only varies slowly when the Mg + ion and He atom approach one another.…”

Communication: Angular momentum alignment and fluorescence polarization of alkali atoms photodetached from helium nanodroplets

“…The corresponding ground and excited state curves were calculated using the helium density and the NaHe and ( and ) Na * -He interactions from Ref. 24.…”

LiHe spectra from brown dwarfs to helium clusters

“…However, an important question to address is whether the small value of the Russell-Saunders-like spin-orbit interaction for the Li atom has to be taken into account to obtain accurate spectral line profiles. This value (∆ SO = 0.34 cm −1 in 2 P state) is only of the order of magnitude of the accuracy of the energies obtained within the framework of methods and extended basis sets described in Dell'Angelo et al (2012). As a result, we believe this effect may be best accounted for if the value of the atomic Li spin-orbit coupling parameter ∆ SO varies slowly when the Li and He atoms approach one another.…”

“…This is crucial to interpret absorption spectra of Li obtained at low temperature (Section 5). Complete details are given by Dell'Angelo et al (2012).…”