Models silicate glass

Figure 7.10. (a) Zachariasen s two-dimensional model of an AiOj glass, after Zachariasen (1932). (b) Two-dimensional representation of a sodium silicate glass,... 

Utilizing this description of silicate glass formation, we suggest models to explain the incorporation of 4+ and 6+ actinide ions in sodium disilicate glass. During cooldown,... 

Corrosion of silicate glasses by alkaline, neutral as well as acidic aqueous solutions can be generally expressed by a simplified mathematical model related to the transfer of the most readily extracted component (alkali ion) and taking into account the interaction of both processes mentioned above ... 

Figure 4.20. Distribution of Q" units in a binary silicate glass, predicted by A. binary distribution model, and B. random statistical distribution model, from Dupree et al. (1987). C. Experimental data for lithium silicate glasses plotted against the line calculated from the binary distribution model (dashed). From Dupree et al. (1990), by permission of Elsevier Seience.

Recently Kowada et al. (28-31) explained the optical propoties of silicate glasses based on energy level stmctures calculated using glassy state cluster models. However they have not yet treated the problem of why the optical properties change with metal oxide content (28-31). We think that PDOS as a function of composition can be used... 

Embedded Cluster Models for Electronic States of Silicate Glasses... 

The discrete variational (DV) Xa method is applied to the study of the electronic structure of silicate glasses in embedded model clusters. The effects of the cluster size, the size of embedded imits, and the Si-0-Si bond angles on the electronic states are discussed. Embeddii units drastically improve the description of the electronic state, when compared to the isolated Si044- cluster, which is the structural unit of silicate glasses e.g., the Fermi energy for the embedded cluster becomes smaller when compared to that of the... 

DFT and ab initio calculations have been made of 170 NMR shielding for the oxides MO (M = Mg, Ca or Sr) and the model species OM6(OH)122 (central O).32 Similar calculations were reported for magnesium and calcium oxides and aluminosilicates.33 170 3QMAS-NMR spectra were used to characterise a series of Ca-Mg and K-Mg silicate glasses.34 Solid adducts of MgCl2 with ethanol were studied by 13CP/MAS-NMR and ll l3C HETCOR experiments.35... 

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