Theoretical study of electron impact with various biological, atmospheric and applied molecules over an extensive range of incident energies from 0,01 to 5000 eV. We employ two different theoretical formalism, viz ab-initio,. R-matrix for low energy calculations and Spherical Complex Optical Potential (SCOP) for intermediate to high energy scattering. The results are consistent at the overlap energy and hence allows us to predict cross sections over such a wide range.