Molecular dynamics evidence of cation medium-range order in CaSiO3 glass

Abstract Molecular dynamics calculations are reported showing medium-range order (m.r.o.) of Ca ions in CaSiO 3 glass, in agreement with recent measurements by Gaskell et al. of the CaCa partial structure factor (p.s.f.); evidence in favor of the presence in the glass of “crystalline” CaSiO 3 domains is also discussed. A close relationship emerges between Ca m.r.o. and charge correlation of Ca with O ions. The total neutron s.f. is also calculated and it appears that the first sharp diffraction peak, typical of vitreous SiO 2 , is replaced by two less pronounced features in CaSiO 3 glass.