Dirac partial wave calculation for electron scattering cross section by nucleic acid bases

Abstract

Differential, total, elastic and inelastic scattering cross sections due to the electron impact on the primary nucleic acid bases, are calculated with relativistic Dirac partial-wave considering a local interaction potential known as spherical complex optical potential model. The electron scattering is modeled by implementing screening-corrected additivity rule, a modified form of independent atom model, over an energy range of 10-20000 eV. Comparisons of results obtained in this work with other theoretical and experimental approaches are also presented.

Simulational and theoretical study of electron scattering cross section by Chlormethine-DNA complex

“…Total elastic and inelastic cross section values calculated with the same Dirac relativistic method related to nucleic acid bases were reported in our previous paper [1], which were used here for applying the screening correction additivity rule of drug and the CGC complex that is shown in figure 6(a). The calculated polarizability and the first excitation energy of the system (Ch.…”

“…Cross sections of each atom (σ i ) along with related coefficients (s i ) add up the total cross section for the molecule. The detailed calculations of the screening coefficient additivity rule were extensively discussed somewhere else [1].…”

“…Two general methods have been used for this matter: chemotherapy and radiotherapy. Various radiation sources could be used in radiotherapy, in some cases electrons as incident beams are utilized [1]. The interaction of these electrons with the DNA bases could eventually lead to single and double-strand breaks in DNA, therefore, such types of radiation are used in radiotherapy to destroy cancer cells [2].…”

“…Electron scattering by atoms in molecules using independent atom model (IAM) or additivity rule (AR) used to serve as preliminary base for such studies, which consider cross section of a simple molecule as the sum of all atoms involved [10]. However, due to the need to consider modifications related to the phenomenon, other methods have been proposed such as screening corrected additivity rule (SCAR) that has a reasonable outcome comparing to previous investigations [1]. Although the model is thought applicable only for large molecules, therefore in the case of macromolecules the method was suggested to be improved by adding a further modification entitled as screening additivity rule for macromolecules (SCARM) [11].…”

Elastic and Electronically Inelastic Cross Sections for the Scattering of Electrons by Pyrrole

“…Among these secondary species, low-energy electrons with energies typically ranging between 1 and 20 eV are the most abundant . Motivated by this context, many theoretical and experimental research groups seek to contribute to the full understanding of electron damage to DNA by conducting studies of electron interactions with precursor molecules such as nucleobases, − sugar structures, amino acids, phosphates, − and also with molecules that can be considered as simple prototypes for larger systems …”