Bruggeman formalism versus "Bruggeman formalism": Particulate composite materials comprising oriented ellipsoidal particles

Two different formalisms for the homogenization of composite materials containing oriented ellipsoidal particles of isotropic dielectric materials are being named after Bruggeman. Numerical studies reveal clear differences between the two formalisms which may be exacerbated: (i) if the component particles become more aspherical, (ii) at mid-range values of the volume fractions, and (iii) if the homogenized component material is dissipative. Only the correct Bruggeman formalism uses the correct polarizability density dyadics of the component particles in the homogenized composite material (HCM) and is directly derivable from the frequency-domain Maxwell postulates specialized for the HCM.