Theoretical Studies of DDCS for Water Molecules by Electron Impact : A New Approach Debora Coimbra*,Ronaldo Santos Barbieri+ and Alexandre Pereira Chahad* *Departamento de Fisica ,+Departamento de Quimica Universidade Federal de Sao Carlos The Binary-Encounter-Bethe(BEB) model, proposed by Kim and Rudd, in 1994, was recently extended by Coimbra & Barbieri to obtain doubly differential cross section (DDCS) for the scattering of electrons by atoms and molecules. DDCS results are presented in comparison to experimental results and the agreement is quite good.