Continuous random network avoidance and microscopic relaxation time in As2Se3 glass

Abstract Recent nuclear magnetic resonance (NMR) studies on SiO2 structural glass has shown a positive correlation exists between Si-O bond lengths and Si-O-Si bond angles. This indicates that when the glass solidified it avoided forming as a continuous random network (CRN). A microscopic tight binding (TB) model was used some years ago to predict the nuclear quadrupole resonance (NQR) distribution of powdered As2Se3 glass. Similar bond length- bond angle correlations were found. Here we extend this model and show that these correlations are directly attributable to a competition between valence electronic energy and emergent frustration forces as the glass solidifies into a locally preferred structure (LPS). Recent studies have shown that fast atomic motion occurs in metallic glasses at temperatures far below the glass temperature. Using this model we calculate a microscopic relaxation time and show it is a product of CRN avoidance.