We demonstrate how a phenomenological model which reproduces first‐principles density functional theory (DFT) calculations can be constructed to study complex ferroelectric oxides. This model is derived from a well‐known crystal chemistry approach, in which Brown’s Rules of Valence[1, 2] are used to determine the configurational energy of the system. Our previous work has shown that this model can be used to explain the atomic interactions in the Pb(Zr1−xTix)O3(PZT) solid solution. We extend this model by parameterizing to a distorted DFT structure as well as a structural minimum. Finally, we shall comment on the applicability of this model for finite‐temperature and composition‐dependent studies. © 2003 American Institute of Physics