Investigation of the electronic and dynamic properties of sodium and caesium exchanged zeolite by MO and MD simulations

• Published in: Molecular simulation Vol. 28; no. 12; pp. 1005 - 1019
• Main Authors: Matsumiya, Masahiko, Takagi, Ryuzo
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 02.12.2002
• Subjects: Caesium; Cluster; Dynamics; Electronic Properties; Md Simulation; Mo Simulation
• ISSN: 0892-7022; 1029-0435
• DOI: 10.1080/0892702021000011043

For the pyrochemical reprocessing of spent metallic fuels in molten salt baths it is of importance to investigate the electronic and dynamic properties of the negative elements like Cs in aluminosilicates framework. The molecular orbital simulation has been performed on three types of clusters and 4A-zeolite frameworks with exchangeable alkali-ions containing as significant fission products in order to estimate the geometry optimization, the vibrational frequency factors and the electric densities, etc. These quantum chemical results enable us to conclude that the most stable structure is consistent with the X-ray results. Moreover, the obtained infrared spectrum was reproduced by the experimental results. Furthermore, the molecular dynamics simulation for Na-A and Cs-A zeolites has been carried out at 673 K in order to investigate the dynamics of Na + and Cs + ions in Na-A and Cs-A zeolite frameworks. These results revealed that Na I ion in β-cage was more stable than the other Na ions in Na-A zeolite and Cs I ion in α-cage was maintained stability in Cs-A zeolite in consideration of the self-diffusion coefficients.