Ionization of phenol by single electron impact: triple differential cross sections

Abstract

Triple differential cross sections (TDCS) for the ionization by single electron impact of the highest and next-highest occupied molecular orbitals of phenol are provided in this work. A first Born approach is used, describing the ejected electron by a distorted wave. The molecular wave functions are developed in a single-center form using the computational chemistry program Gaussian. The TDCSs are calculated for an unknown molecular orientation with the proper average (PA) approach and using four different models. In the distorted wave model (DW) the atoms positions do not intervene in the interaction potential between the incoming electron and the molecular target while in the distorted wave multicenter model (DW-MC) they are taken into account. In the DW-Gamow and the DW-MC-Gamow models, the repulsion between the outgoing electrons is described by adding the Gamow factor to the DW and DW-MC models. In general, all results are in good agreement with the experimental data. A small difference is observed between the DW and DW-MC results in the recoil region. Adding the Gamow factor improves the angular position and the relative amplitude of the two peaks observed in the binary region. When the TDCSs are compared to other theoretical results relying on the orientation averaged molecular orbital (OAMO) approximation, the improved agreement with the experimental data reinforces the importance of the proper average approach.

Theoretical study of (e, 2e) triple differential cross sections of pyrimidine and tetrahydrofurfuryl alcohol molecules using multi-center distorted-wave method

“…In order to be more precise, OAMO approximation was replaced by the proper average (PA) [23][24][25][26] to retrieve the multi-center nature in the ini-tial state. Other calculations based on the Coulomb wave and simplified distorted wave models [27][28][29][30] were also reported in recent years.…”

Coincidence study of core-ionized adamantane: site-sensitivity within a carbon cage?

“…In a series of papers [45][46][47][48] we have proposed a quantum approach to calculate total and differential cross sections for the electron impact ionization of complex molecules (formic acid, tetrahydrofuran, pyrimidine...). By integrating the most differential cross sections (here the triply differential cross sections), we can easily retrieve the doubly differential (DDCS), simply differential and total cross sections.…”

“…The theoretical framework is based on the First Born Approximation (FBA) and the ejected electron is described by a distorted wave (a complete theoretical description of the model is given in 48 ). The molecular wavefunction was computed at the HF/6-31G(d) level over the optimized geometry at the B3LYP/6-31G(d) level, and using Gaussian16 code 49 .…”

“…2.2.1 XPS spectra. In a series of papers [45][46][47][48] we have proposed a quantum approach to calculate total and differential cross sections for the electron impact ionization of complex molecules (formic acid, tetrahydrofuran, pyrimidine. .…”

Theoretical study of (e,2e) triple differential cross section of 1b3g orbital of ethylene by vibrational multi-center distorted-wave method

“…This method was recently extended to more general situations by including the distorted waves of the projectiles, [38,39] called multi-center three-distorted-wave (MCTDW) method. Mouawad et al [40][41][42][43] investigated the TDCSs for molecules in the coplanar asymmetric geometry using a Coulomb wave and a simplified distorted wave methods within the first Born approximation.…”