Periodic model of LTA framework containing various non-tetrahedral cations

• Periodic model of zeolite A structure with various cations has been formulated.
• Ab initio calculations of vibrational spectra for model structures have been done.
• Zeolite A with various guest cations was synthesized and IR spectra measured.
• Theoretical spectra agree well with the experimental ones.
• Detailed analysis of calculated and experimental spectra has been carried out.

A simplified periodic model of Linde Type A zeolite (LTA) structure with various selected mono- and di-valent extra-framework cations was formulated. Ab initio calculations (geometry optimization and vibrational spectra calculations) using the proposed model were carried out by means of Crystal09 program. The resulting structures and simulated spectra were analyzed in detail and compared with the experimental ones. The presented results show that in most cases the proposed model agrees well with experimental results. Individual bands were assigned to respective normal modes of vibration and the changes resulting from the selective substitution of extra framework cations were described and explained.

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