  The absolute elastic differential and Integral (total) cross-sections of
polyatomic molecules by plane and twisted electron beam (Bessel Beam) impact
are presented with $CO_2$ and $N_2O$ as examples. The cross sections are
computed theoretically in the First Born Approximation(FBA). The target
molecules are modeled using multicentered wavefunctions with Gaussian Type
Orbitals(GTOs) and optimized through Density Functional Theory. The electron
density obtained as a function of spatial coordinates is used to calculate the
elastic form factor while considering the active role of all electrons in the
molecule. Coulomb direct potentials are used for the interactions of the
incident beam with all electrons and nuclei. An orientation averaging of the
differential cross-section is performed to mimic experimental situations. The
Young's interference effects due to the nuclei are considered. The cross
sections are calculated at intermediate energies ranging from 300eV to 1keV.
The proposed methodology can certainly be applied to any polyatomic molecule.
The interactions of Bessel beams (Twisted Electron Beam) with topological
charges $m_l$ = 1, 2, and 3 are analyzed. The average over impact parameters of
the differential cross-sections representing the beam's interaction with a
large number of molecules is also studied and presented. Finally, the Integral
elastic cross-section (ICS) of the molecules by plane wave and twisted beams is
calculated and presented.
