Comparative configurational study for He, Ne, and Ar trimers

Abstract

Use of correlated potential harmonic basis functions for the description of the 4He trimer and small clusters J. Chem. Phys. 134, 164106 (2011); 10.1063/1.3583365Bound-state energies in argon trimers via a variational expansion: The effects from many-body corrections Helium trimer bound states are calculated by means of a variational method described in terms of atom pair coordinates and distributed Gaussian basis functions for zero total angular momentum. To show the feasibility of this method, we also apply it to the calculation of the first vibrational levels of the Ar 3 and Ne 3 clusters. Special emphasis is made on the study of the possible Efimov behavior of the first excited state found in the 4 He 3 trimer. Geometrical configurations of the ground and first excited states of these rare gas trimers have been exhaustively studied owing to the proper symmetry of the coordinates chosen.

The structure of a weakly bound ionic trimer: Calculations for the He24H− complex

“…For the 4 He 2 interaction potential we have adopted the one proposed by Aziz and Slaman 20 as in our previous calculations. 16,17,21,22 We report in Fig. 1 the relative shapes and strength values of the 2B potentials considered here: The HeH Ϫ interaction is clearly shallower and more repulsive than the corresponding HeHe potential, as already seen by previous work.…”

“…In a similar way, as discussed earlier by us, 22 the expectation values for the cosine of the angle associated to each X atom, ͗cos X ͘, and higher moments, ͗cos n X ͘, can be easily estimated. Another significant quantity is the root-meansquare ͑rms͒ value of the area ''covered'' by the trimer, ͱ ͗S 2 ͘, where S 2 can be expressed as…”

“…In this way, the deviation from the triangular requirement, as we defined in Ref. 22, is estimated to be lower than 1%.…”

“…As discussed in our previous work, 16,17,21,22 one of the additional interests for the weakly bound three-body aggregates relates to the earlier studies in nuclear physics carried out by Efimov. 31 In this context, a special effect was suggested to occur whenever each dimer involved in the triatomic species has no bound states but does exhibit a zero resonance.…”

Variational description of the helium trimer using correlated hyperspherical harmonic basis functions

“…Following Refs. [16,17,27], we studied the behaviour of 4 He * 3 as a function of the strength of the pairwise interaction. In Fig.5 we plotted the energy difference E 1 − E d of the system as a function of the parameter λ defined by:…”