Bound-state energies in argon trimers via a variational expansion: The effects from many-body corrections

Abstract

In this paper we study the bound-state energies and geometries of Ar 3 for J = 0, using the distributed Gaussian functions method that provides a configurational description of the different structures contributing to these states. Atom-atom potentials are employed and three-body long-range effects are also included in the computational treatment by adding to the sum of potentials the AxilrodTeller triple-dipole correction for the whole rotationless energy spectrum. An estimate of the total number of bound states for the Ar trimer is given. With respect to previous calculations, limited to the lower-lying states, our results show slightly larger nonadditive effects and are further able to predict the full range of the bound spectrum. Changes on the geometries of a large part of the vibrationally excited states of Ar 3 when the Axilrod-Teller term is included in the molecular potential are found by the present study.

Bosonic helium droplets with cationic impurities: Onset of electrostriction and snowball effects from quantum calculations

“…While these contributions are very small in neutral He clusters [28], they may be of some importance when an ionic impurity is present. In the latter case, in fact, the main contribution to the many body interaction terms comes from the fact that the He atoms near the impurity are polarized by the charge and acquire a small dipole moment.…”

Searching for many-body effects and Efimov states in very weakly bound triatomics: HeNeH−and HeNeH

“…[24] and which we know to provide at long range the Axilrod-Teller (AT) contribution to the full interaction [25]. In our previous study on the Ar 3 system, however, we had found [12] that the AT corrections were not very significant and did not substantially modify its spectral structure. Since we are dealing here with much more weakly interacting partners (in the HeNeH three-atom complex, at least) we did not consider it necessary to test its effects on the single bound state of the neutral cluster [14].…”

“…The latter method has been presented many times before [9][10][11][12][13] and therefore only a short summary of its implementation will be given below, referring any interested reader to our earlier publications. Section III describes the 2B potentials employed for the two title systems and the 3B corrections which we have included, while Section IV presents our results.…”

Accurate calculations of bound rovibrational states for argon trimer

“…They do so via London dispersion or more general van der Waals (vdW) interactions. [6][7][8][9][10][11] The resultant "vdW clusters" are thus only weakly bound, and manifest bound states with high probability at extremely large nuclear separations-in comparison, e.g., with covalently bonded species. As a consequence, vdW clusters are inherently "floppy," meaning that they have very strong coupling between their rotational and vibrational degrees of freedom, and also exhibit highly delocalized or "fluxional" bound state wavefunctions.…”