A complex optical model potential modified by incorporating the concept of bonded atom, which takes into consideration the overlapping effect of electron clouds between two atoms in a molecule, is employed to calculate the absolute differential cross sections, the elastic integral cross sections, and the moment transfer cross sections for electron scattering from O2 and CF4 i n the energy range 300—1000eV by using additivity rule model at Roothaan-Hartree-Fock level. The quantitative absolute differential cross section, elastic integral cross secti on, and moment transfer cross section results are compared with those obtained b y experiments and other calculations wherever available, and good agreement is o btained. It is shown that the additivity rule model together with the complex op tical model potential modified by incorporating the concept of bonded atom can g ive better results than the one unmodified by it. So, the introduction of the bo nded-atom concept in complex optical model potential betters the accuracy of the absolute differential cross sections, the elastic integral cross sections, and the moment transfer cross sections.