My view regarding aforementioned models(drude,lorentz,brendel bormann) are models used to characterised optical properties of metals and noble metals such as dielectric function, susceptibilty,refractive index and so on.Hence ,I have studied each of the models.The point I am now is to find a suitable structure :be it regular or irregular nanoparticles to apply any of the models.Can you proffer a suitable method(analytical and numerical) and a structure in which these models be applied to.