Vibrational spectrum of Ar3+ and relative importance of linear and perpendicular isomers in its photodissociation

Abstract

The photodissociation dynamics of the argon ionized trimer Ar + 3 is revisited in light of recent experimental results of (V. Lepère et al., J. Chem. Phys. 130, 194301, 2009), which show that the fragment with little kinetic energy is always a neutral one, thus the available energy is shared by a neutral and ionic fragments, as in Ar + 2 . We show that these results can be interpreted as the photodissociation of the linear isomer of the system. We perform a 3D quantum computation of the vibrational spectrum of the system and study the relative populations of the linear (trimer-core) and perpendicular (dimer-core) isomers. We then show that the charge initially located on the central atom in the ground electronic state of the linear isomer migrates toward the extreme ones in the photoexcitation process, such that photodissociation of the linear isomer produces a neutral central atom at rest, in agreement with measured product state distributions.

Photoabsorption spectrum of helium trimer cation—Theoretical modeling

“…The hyperspherical method, 37,38 employed recently in calculations of He + 3 and Ar + 3 vibrational spectrum and Ar 3 and H + 3 rotational-vibrational spectrum, [39][40][41][42] is used in this work to obtain the accurate wavefunction corresponding to the He + 3 rotational-vibrational ground state. Up to numerical uncertainties, this approach is essentially free of systematic errors and we consider it as a benchmark for the other sampling methods.…”

Accurate calculations of bound rovibrational states for argon trimer

“…In particular, we sum |ψ| 2 over K to obtain a vibrational space density, which is further restricted to a hyperradius ρ fixed to its equilibrium geometry value, ρ equil . Though there are myriad ancillary reasons to plot wavefunctions, including mode analysis, 63 the primary purpose of the wavefunction plots for this work is to identify states that have the correct totally-permutationsymmetric G 12 character. 11 In the plots, these will manifest as states that demonstrate near-perfect sixfold azimuthal rotation symmetry.…”

Computation and analysis of bound vibrational spectra of the neon tetramer using row orthonormal hyperspherical coordinates

“…The method used here to obtain 4-body bound states is an extension of the 3-body roworthonormal hyperspherical harmonics expansion method already used to obtain Ar 3 [31], H + 3 [32], He + 3 [33] and Ar + 3 [34] rovibrational spectra. The Hamiltonian of the system is obtained by adding the 6 dimensional interaction potential of the system V (ρ, θ, φ, δ) to the kinetic energy operator given by eq.…”