In this work, we apply a theoretical method based on the elasticity theory to the optimization of heterointerfaces. The essential idea of the theory is based on the relationship between strain gradient and dynamics as shown by elasticity theory equations which enable to identify the S factor - S=f(c(ij))/rho, where f(c(ij)) are the effective elastic constants and rho the density - as an important parameter of the theory. This theory is then applied to several heterosystems.