ESTIMATE OF IONICITY OF ZEOLITE NAA USING THE FREQUENCY-SHIFT VALUES OF PHYSISORBED MOLECULAR-HYDROGEN

An estimate of the ionicity of the zeolite NaA is given. It is based o n the fitting of the frequency shift value of the fundamental vibratio nal transition in physisorbed molecular hydrogen. The interaction ener gy U is calculated by ion-molecule pairwise addition with the ions of the zeolite. Frequency shift values are calculated as a displacement o f vibrational levels of the fundamental transition due to the interact ion of hydrogen with the zeolite. The level positions are calculated b y integration of the Schrodinger vibrational equation. The contributio ns to the total frequency shift value of a hindered rotation and of a centre of mass vibration are estimated. The influence of the zeolite p arameters on the resulting ionicity is discussed.