Low-energy Electron Scattering from Polyatomic Molecules: The Role of Electron Correlation

Abstract

Until recently the principal barrier to the accurate theoretical description of electronic collisions with polyatomic molecules was the problem of scattering by a nonlocal potential which is arbitrarily asymmetric. The last five or six years have seen the development of numerical techniques capable of solving the potential scattering problem, and the first applications of methods for treating many-body aspects of collisions of electrons with polyatomic molecules are beginning to appear in the literature. We describe the complex Kohn method and the use, in scattering calculations, of methods for treating electronic correlation which are standard in bound-state quantum chemistry. As examples of the application of these ideas we present the results of calculations on electron scattering from CH4, SiH4 and C 2 H6. All of these molecules exhibit Ramsauer-Townsend minima at low impact energies which are entirely correlation effects.

Elastic and total cross sections for electron-carbon disulfide collisions

“…Indeed, the inclusion of the influences of target correlation on electron-molecule scattering cross sections is a difficult task. To date, very few investigations on this subject have been reported in the literature (McCurdy 1992, Lee et al 1990b, Tanaka et al 1998. Recently, we have also investigated the target correlation effects on vibrationally elastic and inelastic electron-H 2 scattering in the 1-60 eV range (Lee and Fujiwara 1998).…”

Elastic and total cross sections for electron scattering by nitrogen molecule in the intermediate energy range

“…On the other hand, to estimate the influences of target electronic correlation on electron-molecule scattering cross sections is a difficult task. To date, very few investigations on this subject have been reported in the literature and most of them were carried out for low incident energies (McCurdy 1992, Lee et al 1990a, Tanaka et al 1998. Recently, we have investigated the target correlation effects on vibrationally elastic and inelastic electron-H 2 scatterings in the 1-60 eV range (Lee and Fujiwara 1998).…”

Low- and intermediate-energy total electron scattering cross sections for and molecules

“…Due to its relatively simple-almost spherical-geometry, the SiH 4 molecule is a convenient target for testing different theoretical models applied to the problem of electron scattering. Calculations of Davenport (1984, 1985), Gianturco et al (1987), Jain andThompson (1987, 1991), , Yuan (1988Yuan ( , 1989, Winstead and McKoy (1990), Tanaka et al (1990), Jain (1991), Sun et al (1992) and McCurdy (1992) have been focused on two conspicuous features of the low-energy cross section: the RT minimum below 0.5 eV and the broad resonant maximum around 3 eV, while Jain (1987), Winstead et al (1991Winstead et al ( , 1992 Jain and Baluja (1992) and Jiang et al (1995) have applied various approaches to calculations of cross sections for higher-impact energies.…”