Rigid ion and Shell model calculations of the frequencies and intensities of the infrared active modes of aluminiumfree sodalite and faujasite are presented. Results of Shell model calculations agree better with experiment than those of Rigid ion calculations. A good agreement of the frequencies in the bending and torsional mode regions is found. One concludes from comparing experimental and calculated frequencies in the stretching modes region that the short range potential for the Si-O stretch frequency is too weak. The improvement of the Shell model versus the Rigid ion model results can be ascribed to screening of the long range electrostatic interactions by polarization of the O2--anions.
|Naam||Studies in Surface Science and Catalysis|
|ISSN van geprinte versie||0167-2991|
|Congres||conference; International Zeolite Conference (IZC) ; 8 (Amsterdam) : 1989.07.10-14; 1989-07-10; 1989-07-14|
|Periode||10/07/89 → 14/07/89|
|Ander||International Zeolite Conference (IZC) ; 8 (Amsterdam) : 1989.07.10-14|