VIBRATIONAL FREQUENCY-SHIFTS OF DIATOMIC-MOLECULES IN INTERACTION WITH A NA-INITIO CALCULATIONS - COMPARISON WITH EXPERIMENT ON H-2 AND N-2ADSORBED IN NAA ZEOLITE( CATION BY AB)

Ab initio calculations on H-2 and N-2 and on the same molecules in the presence of a Na+ cation are presented. The equilibrium configuration and the vibrational frequency shift due to the interaction are calcul ated. The potential energy surfaces are obtained by local osculatory i nterpolations and extrapolations. The vibrational frequencies are calc ulated by the Numerov-Cooley method. The direction of the frequency sh ift is found to be related to the orientation of the diatomic molecule with respect to the cation. The results are compared with experimenta l data on induced infrared bands of H-2 and N-2 adsorbed in NaA zeolit e.