A COMPARATIVE COMPUTER MODELING STUDY OF SPECTRAL CHARACTERISTICS OF CATION-EXCHANGED ZEOLITE-Y

Vibrational spectra of alkali metal exchanged zeolite Y were studied b y means of lattice energy minimization and molecular dynamics. Results of the study show that the mid-infrared spectra are better reproduced with a valence force field used in MD calculations in comparison to t he data calculated with the shell model employed in the energy minimiz ation procedure. Both methods describe the infrared spectra in the far -infared region well. The calculations reveal that no band in the far- infrared region can be unambiguously assigned to cationic vibrations a t a specific site.