Alkali metal trimers

The full quantum mechanical study of nuclear dynamics in molecules has received considerable attention in recent years. An important example of such developments is the work carried out on the prototypical systems H3 [1-5] and its isotopic variant HD2 [5-8], Li3 [9-12], Na3 [13,14], and HO2 [15-18], In particular, for the alkali metal trimers, the possibility of a conical intersection between the two lowest doublet potential energy surfaces introduces a complication that makes their theoretical study fairly challenging. Thus, alkali metal trimers have recently emerged as ideal systems to study molecular vibronic dynamics, especially the so-called geometric phase (GP) effect [13,19,20] (often referred to as the molecular Aharonov-Bohm effect [19] or Berry s phase effect [21]) for further discussion on this topic see [22-25], and references cited therein. The same features also turn out to be present in the case of HO2, and their exact treatment assumes even further complexity [18],... 

S systems, permutational symmetry alkali metal trimers, 712-713 dynamic Jahn-Teller and geometric phase effects, 698-711... 

H3 (and its isotopomers) and the alkali metal trimers (denoted generally for the homonuclears by X3, where X is an 2S atom) are typical Jahn-Teller systems where the two lowest adiabatic potential energy surfaces conically intersect. Since such manifolds of electronic states have recently been discussed [60] in some detail, we review in this section only the diabatic representation of such surfaces and their major topographical details. The relevant 2x2 diabatic potential matrix W assumes the form... 

Photoassociation experiments involving alkali-metal systems have stimulated considerable interest in chemical reactivity in alkali-metal dimer-alkali-metal atom collisions at ultracold temperatures [14]. Rearrangement collisions in identical particle alkali-metal trimer systems occur without energy barrier, and recent studies have... 

At large atom-diatom separations R, the interaction potential can be approximated by an effective potential, composed of a repulsive centrifugal term and the long-range interaction potential. For alkali-metal trimer systems, the atom-diatom long-range potential is a van der Waals interaction potential and behaves as The classical... 

Table 3.4 provides a compilation of zero-temperature quenching rate coefficients for different alkali-metal trimer systems. 

The formalism derived in this section may also be used to obtain a double-sheeted potential energy surface for the alkali metal trimers. Indeed, a... 

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