Physical adsorption of the Ba atom on Ar_n surfaces: spectroscopic and geometric properties

Abstract

Barium atoms cause several environmental and ecological dangers. Numerous techniques are employed to remove the Ba atom such as physisorption and solvation methods. In this work, we are interested in investigating and exploring the Ba atom's physical adsorption on argon surfaces. We have tested several optimizations and we have found that the first range of Ar atoms (n=1-12) presents more than 90 % of the energy interaction between Ba and the adsorbent surface. Therefore, we started by computing and analyzing the potential energy surfaces (PESs) of BaArn molecules. Large basis sets and full Configurations Interaction (full-CI) with the pseudo-potential approach were used to perform the PES, the spectroscopic parameters, vibrational energy levels, and electric dipole moment (EDM) for the selected states. The structural properties and relative stability of Ba (6s21S)Arn (n =1-13, 30, 44 and 54) clusters are determined using Monte Carlo simulation based on the Potential Model method (MC-PM). Several clusters (n > 4) were demonstrated to be stable using MC simulations, and the Ba atom is always present on the surface of the remaining Arn cluster. We have found a good concordance between our results and the available theoretical and experimental data. The spectroscopic information of these complexes can be used by experimental researchers for the investigation of optical mechanisms collision, especially the deformation of the Ba spectrum by collision with the argon surface.