Model of vitreous SiO2 generated by an ab initio molecular-dynamics quench from the melt

Johannes Sarnthein, Alfredo Pasquarello, Roberto Car

Research output: Contribution to journalArticle

168 Scopus citations

Abstract

We studied liquid and vitreous SiO2 by performing first-principles molecular-dynamics simulations. Diffusion in the liquid is shown to occur through correlated jump events, which disrupt the network only for short time periods. The persistence of the network even at high temperatures is confirmed by the average structural properties of the liquid. By quenching from the melt, we obtained a model for the glass, which forms a perfectly chemically ordered network. Structural and electronic properties of our model glass present a remarkable agreement with vitreous SiO2: the calculated total structure factor closely agrees with data from neutron diffraction experiments and features in the x-ray photoemission spectrum are well reproduced by the electronic density of states. This agreement strongly supports other structural properties which are yet unavailable from experiment such as partial pair correlation functions and bond-angle distributions. A comparative study of the electronic density of states in liquid, vitreous, and crystalline SiO2 shows that enhancement of disorder gives rise to a reduction of the gap.

Original languageEnglish (US)
Pages (from-to)12690-12695
Number of pages6
JournalPhysical Review B
Volume52
Issue number17
DOIs
StatePublished - Jan 1 1995

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Model of vitreous SiO2 generated by an ab initio molecular-dynamics quench from the melt'. Together they form a unique fingerprint.

  • Cite this