Angular momentum disposal

Brouard, M., Martinez M.T., O Mahony, J., and Simons, J.P. (1990). Energy and angular momentum disposals in the vibrationally mediated photodissociation of HOOH and HOOD. Intramolecular properties via photofragment mapping, Mol. Phys. 69, 65-84. 

Measurements of product rotational alignments therefore provide a measure of angular momentum disposal. 

Following the quenching process further, the system is described best in the body-fixed frame, at least for the smaller internuclear distances. Then no orbital angular momentum can be transferred to the relative internuclear motion lz = 0, and the question arises as to how the electronic orbital angular momentum Lz = 1 of the 3p II) state of Na should be disposed of since the final state has to be 3s 2). The obvious solution is to change the orientation of the molecular angular momentum j, that is, to induce a Aiz= 1 transition in the molecule and thus maintain a constant... 

However, with the exception of a few coplanar studies, all other quantum calculations have been for ID systems. The extent to which ID calculations form a satisfactory basis to explain the energy disposal in chemical reactions varies from reaction to reaction and, in the absence of experimental information or more approximate calculations, is impossible to assess. Collinear calculations need to be transformed to three dimensions in an attempt to incorporate the effects of orbital and rotational angular momentum which are absent in the ID calculations and produce more realistic product energy distributions [149,150]. Such methods appear to work most effectively for reactions whose dynamics are predominantly collinear. 

Experiments have also been performed to study the effect of reagent translation excitation on the reactivity of K + HC1 [284] and the effect of reagent vibrational and rotational energy for Na + HF, HC1 [65, 285] and K + HC1 [286, 287]. These experiments have not probed the effect on the energy disposal of the increase in reagent energy. The polarisation of the MX product angular momentum has been studied [288] for K, Cs + HBr, HI. 

A number of processes including refrigeration (to keep the clouds cool) and accretion disks (to dispose of angular momentum) enable these dark clouds to collapse under their own gravity until they are sufficiently dense and hot for nuclear reactions to begin. At this point, we consider a star to have been bom. 

Since we have in addition the principle of the conservation of the total angular momentum at our disposal the integration can be completely carried out. We can take the hitherto arbitrary axis of i in the direction of the resultant angular momentum. Since the nodal line is perpendicular to this, the angular momentum about the nodal line will be... 

For instance, a wheel consisting of N identical pieces disposed at the same distance from the center (same inertia), sees its angular momentum given by N times the angular momentum of each piece. 

Study. The reason is that transition state theory concentrates on the behaviour of the system up to the dividing surface, whereas the product energy disposal is determined by the potential felt by the fragments as they separate. However, Marcus, Wardlaw and Klippenstein have proposed an extension that describes the evolution of the transitional modes along the reaction coordinate and that, at the same time, conserves angular momentum. 

The conservation of angular momentum puts two conditions at om disposal the direction of L is conserved and the magnitnde of L is conserved. The two following subsections make use of these two conditions. 

---