Weakly bound states of the He-He-Ca triatomic system

Abstract

We investigate for the existence of the weakly bound He-He-Ca molecules. By employing the best empirical interaction between each pair of particles, the Schrödinger equation for the triatomic system is solved using hyperspherical coordinates in the adiabatic approximation. The bound states are found for each of the 3 He-3 He-40 Ca, 3 He-4 He-40 Ca, and 4 He-4 He-40 Ca trimers, respectively. The binding energies of such molecules are estimated. We discuss the features of the channel functions associated with the hyperspherical potential curves of each system to obtain insight into the geometry of the molecules.

Binding energies and structures of Ca-He2weakly bound triatomic complexes

“…Apart from the mass effect, bosonic and singlet fermionic nonrotating species are very similar, as their spatial wave functions should be totally symmetric, and the corresponding energies do not differ too much. The present results are completely different from those of Gou and Li [16] who report four bound levels for the fermionic complex, although three of them were above the Ca-3 He+He dissociation limit, and 31 bound levels for the bosonic complex (the first one was below the global minimum of the PES, as already mentioned, and up to 27 levels above the corresponding dissociation limit).…”

“…The values produced by the Ca-He interaction [15], −4.740 K and −5.626 K for the lighter and heavier helium isotope, respectively, agree with those reported in Ref. [16]. As expected, when considering the less deep Ca-He potential of Ref.…”

“…Hence, and even for a totally rigid Ca-He 2 complex, the energy value reported for the ground level of the bosonic system in Ref. [16] becomes unphysical.…”

“…[15]. Here, in an attempt to shed some light on the reliability of the intriguing results reported by Gou and Li [16], we present three different calculations on the bound levels, and on their corresponding structures, for bosonic Ca-4 He 2 and fermionic Ca-3 He 2 complexes. In addition, we try to clarify the situation with respect to the differences in the Ca-He interaction as described by the two above-mentioned potentials.…”

“…The interest in the existing potentials for describing the interactions within the triatomics under study here has been renewed by recent investigations performed by Gou and Li [16], who employed the Ca-He potential of Ref. [15] to calculate the bound states of the Ca-He 2 system.…”