Interaction-induced scattering

H. Versmold and U. Zimmermann. Density dependence of interaction-induced scattering Contributions to the depolarized Rayleigh band of ethane. J. Chem. Soc. Faraday Trans. 2, 53 1815-1824 (1987). 

With the exception of the scanning probe microscopies, most surface analysis teclmiques involve scattering of one type or another, as illustrated in figure A1.7.11. A particle is incident onto a surface, and its interaction with the surface either causes a change to the particles energy and/or trajectory, or the interaction induces the emission of a secondary particle(s). The particles that interact with the surface can be electrons, ions, photons or even heat. An analysis of the mass, energy and/or trajectory of the emitted particles, or the dependence of the emitted particle yield on a property of the incident particles, is used to infer infomiation about the surface. Although these probes are indirect, they do provide reliable infomiation about the surface composition and structure. 

F. Barocchi, M. Celli and M. Zoppi. Interaction-induced translational Raman scattering in dense krypton gas Evidence of irreducible many-body effects. Phys. Rev. A 38 3984, 1988. 

Naively one could think that scattering on weak barriers cannot possibly yield a sharp peak in G(eo, T). Indeed, the transmission probability as a function of e does not have any peak at e = eo, in contrast to the case of resonant tunneling. At high T, G(eo,T) is a weakly oscillating (with a period A) function of eo- The only difference with the non-interacting case is an enhanced amplitude of the oscillations. In fact, however, the interaction-induced vanishing of the transmission probability at ep for T = 0 does lead to a narrow Lorentzian peak of G(eo,T), provided that T is low enough and the barriers are not too asymmetric. 

Potential energy surfaces of weakly bound dimers and trimers are the key quantities needed to compute transition frequencies in the high resolution spectra, (differential and integral) scattering cross sections or rate coefficients describing collisional processes between the molecules, or some thermodynamic properties needed to derive equations of state for condensed phases. However, some other quantities governed by weak intermolecular forces are needed to describe intensities in the spectra or, more generally, infrared and Raman spectra of unbound (collisional complexes) of two molecules, and dielectric and refractive properties of condensed phases. These are the interaction-induced (or collision-induced) dipole moments and polarizabilities. 

Geiger LC, Ladanyi BM. Higher order interaction-induced effects on Rayleigh light scattering by molecular liquids. J Chem Phys 1987 87 191-202. 

V. Teboul and S. Chaussedent, Cutoff effect in molecular dynamics simulations of interaction induced light scattering spectra, Comput. Phys. Commun., 105 (1997), 151-158. 

Collision-induced light scattering is the name for the Raman spectroscopy that arises from the interaction-induced variations of the polarizability of a sample. For a description of the scope of CILS, we consider briefly two somewhat extreme cases, a tenuous gas and a liquid. 

In general, the polarizability is a tensor whose invariants, trace and anisotropy, give rise to polarized and fully depolarized light scattering, respectively. Collision-induced light scattering is caused by the excess polarizability of a collisional pair (or a larger complex of atoms or molecules) that arises from the intermolecular interactions. In Section I.l, we are concerned with the definition, measurement, and computation of interaction-induced polarizabilities and their invariants. 

F. Barocchi, M. Zoppi, U. Bafile, and R. Magli. The pair polarizability anisotropies of Kr and Xe from depolarized interaction induced light scattering spectra. Chem. Phys. Lett., 97 135-138 (1983). 

U. Balucani and R. Vallauri. Tow-body dynamics in fluids as probed by interaction-induced light scattering. Canad. J. Phys., 59 1504-1509 (1981). 

F. Barocchi. Interaction induced light scattering as a probe of many-body correlations in fluids. 5. Phys. (Paris), 46 C9.123-C9.128 (1985). 

F. Barocchi and M. Zoppi. Depolarized Interaction Induced Light Scattering Experiments in Argon, Krypton, Xenon. In G. Birnbaum (ed.), Phenomena Induced by Intermolecular Interactions, Plenum Press, New York, 1985, pp. 311-343. 

G. Briganti, D. Rocca, and M. Nardone. Interaction induced light scattering First and second spectral moments in the superposition approximation. Molec. Phys., 59 1259-1272 (1986). 

T. Bancewiez, S. Kielich, and W. A. Steele. Interaction induced Rayleigh light scattering from molecular fluids by projection operator technique. Molec. Phys., 54 637-649 (1985). 

B. M. Ladanyi. Higher-order interaction-induced effects on depolarized light scattering from fluids of optically anisotropic molecules. Chem. Phys. Lett., 121 351-355 (1985). 

T. A. Litovitz and C. J. Montrose. Interaction Induced Light Scattering in Liquids Molecular Motion and Structural Relaxation. In J. van Kranendonk (ed.), Intermolecular Spectroscopy and Dynamical Properties of Dense Systems—Proceedings of the International School of Physics Enrico Fermi, Course LXXV, North-Holland, Amsterdam, 1980, pp. 307-324. 

R. A. Stuckart, C. J. Montrose, and T. A. Litovitz. Comparison of Interaction Induced Light Scattering and Infrared Absorption in Liquids. In Faraday Symposium of Chemical Society Newer Aspects of Molecular Relaxation Processes, No. II, Chemical Society, London, 1977, pp. 94-105. 

M. Zoppi and G, Spinelli. Interaction induced translational Raman scattering of liquid argon The spectral moments. Phys. Rev. A, 33 939-945 (1986). 

V. Mazzacurati, C. Pona, G. Signorelli, G. Briganti, M. A. Ricci, E. Mazzega, M. Nardone, A. De Santis, and M. Sampoli. Interaction induced light scattering the translational spectra of ice 7 single crystals. Moke. Phys., 44 1163-1175 (1981). 

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