Electron-molecule scattering

Lawrence Berkeley National Laboratory, CA, USA Thomas N. Rescigno 

CK = complex Kohn PSCF = polarized self-consistent field SE = static exchange. 

electron impact can excite any dissociative state of a molecule and reduce it to fragments, and this is a key mechanism by which radicals and molecular fragments are produced in situations ranging from planetary atmospheres to molecular beam sources from experiments in molecular collisions. Another important process is electron-impact ionization, because this is the mechanism by which ions are created in any gas discharge system, and because it can produce any ionic state of the target. 

The simple observation that the mass of the projectile in an electron-molecule collision is at least three orders of magnitude less than that of the reduced mass associated with any 

With these ideas in mind we can make a partial catalog of the processes in electron-molecule collisions. 

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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)... 

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. 

The R-matrix method, which has been used extensively in studies of electron-molecule scattering, has also been applied to positron-molecule scattering, notably by Tennyson and his collaborators (Tennyson, 1986 ... 

M. Berman, H. Estrada, L.S. Cederbaum, W. Domcke, Nuclear dynamics in resonant electron-molecule scattering beyond the local approximation The 2.3-eV shape resonance in N2, Phys. Rev. A 28 (1983) 1363. 

Introduced in the context of heavy-particle reactive collisions [440], the complex Kohn method has been successfully applied to electron-molecule scattering [341], It is accurate but computationally intensive, since continuum basis orbitals do not have the Gaussian form that is exploited in most ah initio molecular bound-state studies. The method has been implemented using special numerical methods [341] developed for these integrals. These numerical methods mitigate another practical... 

Other asymptotic forms consistent with unit Wronskian define different but equally valid Green functions, with different values of the asymptotic coefficient of u>i. In particular, if w k 2 exp i(kr — ln), this determines the outgoing-wave Green function, and the asymptotic coefficient of w is the single-channel F-matrix, F sin ij. This is the basis of the T-matrix method [342, 344], which has been used for electron-molecule scattering calculations [126], It is assumed that Avf is regular at the origin and that Ad vanishes more rapidly than r 2 for r — oo. 

Nesbet, R.K. (1996). Nonadiabatic phase-matrix method for vibrational excitation and dissociative attachment in electron-molecule scattering, Phys. Rev. A 54,... 

Cederbaum, L.S. and Domcke, W. (1981). Local against nonlocal complex potential in resonant electron-molecule scattering, J. Phys. B 14,4665-4689. 

Dub6, L. and Herzenberg, A. (1979). Absolute cross sections from the boomerang model for resonant electron-molecule scattering, Phys. Rev. A 20, 194-213. 

Mazevet, S., Morrison, M.A., Boydstun, O. and Nesbet, R.K. (1999). Adiabatic treatments of vibrational dynamics in low-energy electron-molecule scattering,... 

Morrison, M.A. (1988). Near-threshold electron-molecule scattering, Adv. At. Mol. Phys. 24, 51-156. 

Nesbet, R.K. and Grimm-Bosbach, T. (1993). Use of a discrete complete set of vibrational basis functions in nonadiabatic theories of electron-molecule scattering, J. Phys. B 26, L423-L426. 

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