Scattered molecules

Figure A3.9.4. The ratio of specular reflectivity to incident beam intensity ratio for D2 molecules scattering from a Cii(lOO) surface at 30 K [21],...

Truhlar D G (ed) 1984 Resonances in Electron-Molecule Scattering, van der Waals Complexes, and Reactive Chemical Dynamics (ACS Symp. Ser. 263) (Washington, DC American Chemical Society)... 

Figure C3.3.6. Doppler-line profiles for molecules scattered into the CO COO O J= 72) state by collisions with hot methylpyrazine molecules as depicted by the equations above each half of the figure. The energy of methylpyrazine...

Figure C3.3.7. In the upper half of the figure are shown typical measured Doppler profiles for molecules scattered into the (OO O J= 72) or (OO l J = 17) states of CO2 by collisions with hot pyrazine having an energy of 40 640 cm In the lower half of the figure is shown a typical intennolecular potential identifying the hard and soft collision regimes and the kind of energy transfer they effect.

This total intensity is made up of single molecule scattering... 

Figure 2. togular distribution of the relative scattered intensity of hydrogm molecules scattered from a) Ni(110) b) M(111). The angle of incidenoe of the molecular beam and ibe azimuthal orlentaticn of the surface are indicated in the figure. 

Fig. 10. The emerging picture of electronically nonadiabatic interactions of NO molecule scattering at a metal surfaces. Transition from the ground electronic state to an anionic state which is strongly attractive to the metal surface can be accomplished by high translational energy when vibrational excitation is low (black trajectory). When vibrational motion is highly excited, even low translational energies allow transition of the anionic state (red trajectory). Recently, Monte-Carlo wavepacket calculations have been carried out which tend to support this picture.63...

While for a given surface the incident and scattered molecules have different energies (unless ac = 0), the molecule scattered from surface 1 is the molecule that is incident for surface 2. That is, since there are no gas-gas collisions when the molecule travels between the two surfaces, there is no mechanism to change the energy that it has when it leaves surface 1. Likewise, the energy of the molecules scattered from surface 2 is the same as the energy of those molecules incident upon surface 1. Thus, the temperatures are related by... 

The induced dipole is seen to oscillate at the frequencies z/, v — 2vR and v + 2vr. As a consequence, the molecules scatter radiation at these... 

As in scattering theory in general, one can treat the role of V in either a time independent or a time dependent point of view. The latter is simpler if the perturbation V is either explicitly time dependent or can be approximated as such, say by replacing the approach motion during the collision by a classical path. Algebraic methods have been particularly useful in that context,2 where an important aspect is the description of a realistic level structure for H0. Figure 8.3 is a very recent application to electron-molecule scattering. 

Alhassid, Y., and Shao, B. (1992a), Algebraic Eikonal Approach to Electron-Molecule Scattering. I. Generalized Formalism, Phys. Rev. A 46, 3978. 

Brown, S.C. Electron-Molecule Scattering. Wiley New York, 1979. 

Describe briefly what is meant by light scattering and the mechanism by which molecules scatter light. 

Binary molecular collisions are generally described in terms of various scattering cross sections Q. In the case of a beam scattering experiment, we have a beam of particles, type 1, of velocity v, incident on a target chamber of volume F which is filled with a gas of N2 — Vn2 particles of type 2, with negligible velocites, v2 < v. The total number of beam molecules scattered into all angles per unit time is given by... 

---