A unified description of a series of Phonon properties of potassium halides (KCl, KBr, KI and KF) by means of van der Waals three-body force shell model (VTBFSM) is presented in this paper. This model includes van der Waals interactions (VWI) and three-body interactions (TBI) in the framework of both ion polarizable rigid shell model (RSM). In fact the present model (VTBFSM) has revealed much better descriptions of IR/Raman spectra and anhormonic properties and other dynamical properties of potassium halides .Behavior of potassium halides has been investigated theoretically by using van der Waals three-body force shell model (VTBFSM). A comparative study of the dynamical behavior of all these halides has also been done between the halides in present models. Good agreement has been observed between the theoretical and experimental results, which give confidence that it is an appropriate model for the complete description of ionic crystals with NaCl structure
