Stationary localized states due to quadratic nonlinearity in one dimensional systems

We investigate the effect of a nondegenerate quadratic nonlinear dimeric impurity on the formation of stationary localized states in one dimensional systems. We also consider the formation of stationary localized states in a fully nonlinear system where alternative sites have same nonlinear strengths. Appropriate ansatzs have been chosen for all the cases which reproduce known results for special cases. Connection of the stability of a state with its energy is presented graphically.