Cross-section and asymmetry-parameter calculations for the outer- and inner-valence photoionization of ethane

Abstract

We have computed cross sections and asymmetry parameters for the outer- and inner-valence photoionization of ethane using the Schwinger variational method with Pade corrections. The calculated total cross section is found to be in rather good agreement with the available electron-impact and photoabsorption measurements. One-electron resonant processes in the (1e(g))(-1), (3a(1g))(-1), and (2a(1g))(-1) ionization channels were examined comparing resonant states predicted from the virtual orbitals of a minimum basis set self-consistent-field (MBS-SCF) calculations with scattering resonances found using a local model potential for the electron-molecule interaction. The analysis of the interaction potential in terms of adiabatic radial components provides a description of the mechanism of the resonant trapping

Interference effects in photoelectron asymmetry parameter (β) trends of C 2s−1states of ethyne, ethene and ethane

“…As a result also here a half-wave oscillation could be appreciated, with the β values crossing again at about 200 eV KE, but starting somehow later than in C 2 H 2 , so that the period of the oscillation appears noticeably shorter, in line with the results for cross-section ratios [11], and the expectations based on the inverse correlation with increasing bond length. Photoelectron β values for ethane have previously been calculated for low photon energies up to 40 eV [28]. With the binding energies of our states of interest being ∼24 and ∼20.5 eV, this does not overlap with the data presented here.…”

Symmetry- and multiplet-resolved N1sphotoionization cross sections of theNO2molecule

“…In the ASME method, the resonant energies are determined by locating the poles of the scattering matrix on the unphysical sheet of the complex plane [36] and the corresponding wave function is then extracted and analyzed. The ASME method has been widely used in recent years by our group [12,35,37,38] for the characterization of shape resonances in terms of "dynamical" trapping of high-l partial waves in the molecular range of the effective scattering potential. An interpretation of these resonant processes as one-electron transitions to virtual antibonding MOs can be drawn from the comparison between the continuum ASME orbitals and virtual molecular orbitals obtained from minimum basis set (MBS) calculations.…”

Polyatomic Molecules

“…Absolute Partial Cross Sections(Toffoli, et al, 2004) Calculated absolute partial cross-sections (Mb) for outer and inner valence shells calculations shown are from the mixed dipole length and velocity forms. Taken from Tof 04 À, (1e g ) À1 ; x, (3a 1g ) À1 ; þ, (1e u ) À1 ; o, (2a 2u ) À1 ; V, (2a 1g ) À1 .…”