Low to intermediate energy elastic electron scattering from dichloromethane (CH2Cl2)

We report a theoretical-experimental investigation of electron scattering by dichloromethane (CH2Cl2 ) in the low- and intermediate energy ranges. Experimental elastic differential cross sections (DCS), in the incident electron energy range of 0.5-800 eV and scattering angle range of 10 degrees-130 degrees, were measured using a crossed beam relative flow technique. Integral and momentum transfer cross sections were determined from the experimental DCS. Theoretical elastic differential, integral, and momentum-transfer, as well as grand-total, and total absorption cross sections were also calculated for impact energies ranging from 0.5 to 500 eV. A complex optical Hartree-Fock potential represented the electron-target interaction and a single-center expansion method combined with a Pade approximation was used to solve the scattering equations. Three resonances: a (2)A(1) C-Cl k sigma* resonance centered at about 3.5 eV, a B-2(2) C-Cl k sigma* resonance centered at about 5 eV and a broad (2)A(1) C-H k sigma* resonance at about 10 eV were detected in our calculation. Further calculations of DCS were performed at an intermediate energy range of 50-800 eV, using the independent-atom model in which the atomic complex optical potential and partial-wave method were used to obtain atomic scattering amplitudes. Comparisons of our experimental and theoretical data with very recent experimental and theoretical results are made.