Regular and irregular vibrational states: Localized anharmonic modes and transition-state spectroscopy of Na3

Abstract

Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. We have calculated the lowest 900 vibrational energy levels and wave functions for the quartet (1 4 A 2 Ј) state of Na 3 . The equilibrium geometry of the trimer is triangular, but the calculations include many states that lie above the barrier to linearity. Most of the high-lying states are irregular, but there are a few relatively localized states embedded in the irregular bath. The localized modes observed include a ''horseshoe'' mode and a symmetric stretch centered on the linear transition state. The density of states and couplings are such that in most cases the ''horseshoe'' character is spread over several bath states, while the symmetric stretch states exist in a purer form. The localized states could be observed in laser-induced fluorescence, stimulated-emission pumping or ion photodetachment spectroscopy from a state with a linear equilibrium geometry.

Potential energy surface and bound states of the (X4Σ)KRb‐K complex

“…A reduction from the dimer to the trimer equilibrium distance is always obtained, ranging in the 10–25%. Bound states calculations of quartet states of Na 3 show a good agreement between the experimental and the theoretical spectra and the calculated vibrational frequencies of the two normal modes are ν 1 =37.1 cm −1 and ν 2 =40.8, 44.7 cm −1 for Ref. and ν 1 =38 cm −1 and ν 2 =41 cm −1 for Ref.…”

“…. In the region of high‐lying states two special cases are found, which result to be also present in Ar 3 : “horseshoe” and “linear symmetric stretch” states; the former being characterized by a motion in which the molecule passes from one equilateral triangle geometry to another equivalent geometry (one atom moves between the other two and the outer atoms move apart to make room for it) . The study of the Li+Li 2 collisions at its quartet states showed that for low initial vibrational states the quenching rates are not suppressed for fermionic atoms; while for ( )K+( )K 2 the vibrational quenching is much faster than elastic scattering in the ultralow‐temperature regime .…”

Approach to chaos in ultracold atomic and molecular physics: Statistics of near-threshold bound states for Li+CaH and Li+CaF

“…The situation is more complicated for highly excited states, such as the near-dissociation states that give rise to Feshbach resonances in the present work. Some highly excited states have unstructured nodal patterns that fill the energetically accessible space, but there are others with simple nodal patterns that sample restricted regions of space [67][68][69][70]. However, the paths along which such states are localized may be complicated ones that do not correspond to obvious quantum numbers.…”

Role of the middle and long range parts of the NO2 potential energy surfaces: anomalous density of states and recombination rate constant

“…This is in fact erroneous, because the vicinity of the (first) dissociation threshold of a polyatomic molecule also corresponds to the vicinity of the ZPE of its products. More generally, in the vicinity of the bottom, 21 an isomerisation (or potential) barrier, 22,23 or the dissociation limit of a PES, 19 quantum effects cannot be ignored and SC methods (based on phase space volume derivation) may provide wrong results. In the particular case of a dissociation limit, quantum effects manifest again in a dramatic way below the first dissociation threshold, if the PES extends to large inter-nuclear distances (because of long-range interactions) over an energy range smaller than one excitation quantum in the intramolecular modes (i.e.…”