Forward-backward scattering molecule

Because the sense, or sign, of chiral asymmetry in the forward-backward electron scattering asymmetry depends on the helicity of the photon and of the molecule, it is essential that these variables are properly specified in any study to permit meaningful comparisons to be made. Discussing and comparing quantitative asymmetry factors, y [Eq. (8)] and dichroism [Eq. (9)] likewise requires agreement on the convention adopted in the definition of these terms. 

Figure 12, Schematic mechanism for impulsive reaction of thermal energy reaction of K with oriented CF3I. The electron is assumed to be transferred at large distance to the molecule irrespective of orientation. The molecular ion is formed in a repulsive state that promptly dissociates, ejecting the T ion in the direction of the molecular axis, and the K is dragged off by the departing T resulting in backward scattering for heads orientation and forward scattering for tails as observed.

In the case of the reverse CT calculations, a different picture was obtained. There are many accessible rotational states of the HF molecule which can be populated at the nominal experimental energies. Therefore, the reverse CT studies had to be done for a variety of rotational states. It was found that all rotational states for HF In the v=3 state yielded backwards scattering, but several of the most probable rotational states for HF with v=2 yielded sideways scattering. It was felt by RPB that these results point up a technical problem with the forward CT calculations having to do with boxing of the HF rotational-vibrational states. In the reverse CT... 

From Figure 1 it is clear that the reactive T-atom peak observed in Figure 3 corresponds to forward scattering of the T atoms (and, by momentum conservation, backward scattering of the companion KBr molecules) with respect to the initial K-atom velocity vector. Schematically, the collision proceeds in the following manner ... 

Theoretical work on inhomogeneous molecular distributions is as yet incomplete, but McNulty et al 6) have made some calculations on adsorbed molecules on the surface of particles. Their conclusion was that the angular distributions have structure and that the inelastic scattering intensity in the forward and backward directions is particularly sensitive to particle size. 

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