Evaluation of Electron-Impact Ionization Cross Sections for Molecules.

Area of Science:

• Atomic and Molecular Physics
• Electron-Molecule Interactions
• Computational Chemistry

Background:

• Accurate calculation of ionization cross sections is crucial for understanding electron-molecule interactions.
• Existing theoretical models for molecular ionization present challenges in accuracy and applicability.
• Semiempirical methods offer a computationally efficient alternative for complex systems.

Purpose of the Study:

• To present recent advancements in the Jain-Khare semiempirical approach for electron impact ionization.
• To evaluate ionization cross sections for carbon dimer (C2) and carbon trimer (C3) using this method.
• To validate the semiempirical approach by comparing results with other theoretical models.

Main Methods:

• Application of the Jain-Khare semiempirical method for calculating ionization cross sections.
• Computation of single-differential and integral ionization cross sections for C2 and C3.
• Comparison with existing theoretical calculations including Binary-Encounter-Dipole, Spherical-Complex-Optical-Potential, DM model, and Schwinger variational methods.

Main Results:

• Calculated single-differential ionization cross sections for C2 and C3 as a function of ejected electron energy.
• Derived integral ionization cross sections for C2 and C3 across a wide energy range.
• Demonstrated satisfactory agreement between the semiempirical calculations and available theoretical data.

Conclusions:

• The Jain-Khare semiempirical approach provides reliable ionization cross sections for molecules like C2 and C3.
• The study validates the efficacy of semiempirical methods in electron-molecule ionization studies.
• This work establishes a foundation for applying the method to larger and more complex molecular systems.