Total ionization cross section of cyclic organic molecules.

Area of Science:

• Physical Chemistry
• Atomic and Molecular Physics
• Computational Chemistry

Background:

• Paucity of ionization cross-section data for cyclic organic molecules.
• Importance of ionization data for industrial, biological, and astrophysical applications.

Purpose of the Study:

• Calculate total ionization cross section (Qion) for cyclic organic molecules from threshold to 5 keV.
• Employ and validate two independent computational methods: Binary-encounter Bethe (BEB) and complex scattering potential-ionization contribution (CSP-ic).
• Provide reliable ionization data for molecules with limited existing literature.

Main Methods:

• Utilized the Binary-encounter Bethe (BEB) method in combination with the ωB97X functional.
• Employed the complex scattering potential-ionization contribution (CSP-ic) method.
• Calculated static polarizability to assess data consistency.

Main Results:

• BEB/ωB97X method showed good agreement with experimental data, CSP-ic results, and Irikura orbital energy calculations.
• Total ionization cross sections calculated for most targets over a wide energy range for the first time.
• Observed a linear relationship between maximum ionization cross section and static polarizability, confirming data reliability.

Conclusions:

• The BEB/ωB97X method provides reliable total ionization cross sections for cyclic organic molecules.
• The calculated data are consistent and suitable for applications in industrial processes, radiation biology, and astrophysics.
• This work significantly expands the available ionization data for these important molecular systems.