title: Molecular dynamics study of CaSiO(3)-MgSiO(3) glasses under high pressure.
abstract: The pressure-induced structural evolutions of CaSiO(3)-MgSiO(3) glasses have been examined by means of molecular dynamics simulation. Our calculations revealed that Si coordination remained unchanged up to 15 GPa, while modifier cations caused significant changes in the short-range order structure. In the present study, we conclude that the main compression mechanisms for CaSiO(3)-MgSiO(3) glasses are: (1) the Si-O-Si angle reduction, (2) the coordination increase of Ca and Mg cations, and (3) the compaction in the medium-range scale. Furthermore, small changes in the Q(n) distribution suggest pressure-induced disproportionation reactions. Similar pressure responses between CaSiO(3)-MgSiO(3) glasses may imply that the structural changes of SiO(4) framework units are more significant than those of interstitial cations, Ca and Mg.
authors.affiliation: Department of Earth Sciences, Faculty of Science, Kanazawa University, Kanazawa 920-1192, Japan. Advanced Technology Research Laboratories, Nippon Steel Corporation, 20-1 Shintomi Futtsu, 293-8511, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Shimoda
authors.forename: Masayuki
authors.initials: M
authors.lastname: Okuno