We present extensive modeling of the amorphous silica surface, aimed at connecting its structural and chemical features. beta-cristobalite surfaces are initially studied to model the hydroxylated surfaces. A model reconstruction of the (111) surface is used to define a path leading to the formation of two-membered silicon rings upon dehydroxylation. Subsequently, a realistic model of the amorphous dehydroxylated (dry) surface is produced, by full ab initio annealing of an initial model generated by classical simulation. The presence of surface two-membered silicon rings emerges naturally. A calculation of IR activity yields an associated peak doublet in agreement with experimental data.
Two-membered silicon rings on the dehydroxylated surface of silica / Ceresoli, C.; Bernasconi, M.; Iarlori, S.; Parrinello, M.; Tosatti, Erio. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 84:17(2000), pp. 3887-3890. [10.1103/PhysRevLett.84.3887]
Two-membered silicon rings on the dehydroxylated surface of silica
Tosatti, Erio
2000
Abstract
We present extensive modeling of the amorphous silica surface, aimed at connecting its structural and chemical features. beta-cristobalite surfaces are initially studied to model the hydroxylated surfaces. A model reconstruction of the (111) surface is used to define a path leading to the formation of two-membered silicon rings upon dehydroxylation. Subsequently, a realistic model of the amorphous dehydroxylated (dry) surface is produced, by full ab initio annealing of an initial model generated by classical simulation. The presence of surface two-membered silicon rings emerges naturally. A calculation of IR activity yields an associated peak doublet in agreement with experimental data.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.