Study of the effect of sizes on the structural properties of SiO2 glass by molecular dynamics simulations

Abstract To validate the present model and different simulation results of SiO 2 considering 169,956 atoms, the total correlation function of solid SiO 2 obtained by the present simulation is compared with that of the experimental results obtained by Poulsen et al. [14] and agrees well with the experimental results. To understand the effect of model size on the physical and chemical properties of solid SiO 2 , SiO 2 is formed using four different sizes of model considering the total number of Si and O atoms 666, 5808, 169,956 and 339,915 in the ratio 1:2 using the parameters of Si Si, Si O, and O O in Tersoff potential obtained by Munetoh et al. [40] by the molecular dynamics simulations. The effect of model sizes on the partial radial distribution functions of Si Si, Si O, and O O with the total radial distribution function of solid SiO 2 as a function of radial distance is studied. Besides, the effect of model sizes on the bond angle distribution of Si O Si and O Si O with angle, and bond density of Si Si, Si O, and O O in solid SiO 2 as a function of radial distance is studied. All of the physical and chemical properties in liquid and solid states of SiO 2 are studied during the simulation of SiO 2 considering 169,956 atoms and if the model size is increased beyond this size, no size effect is observed on the physical and chemical properties of SiO 2 . The obtained physical and chemical properties like partial radial distribution functions of Si Si, Si O, and O O and total radial distribution function of liquid and solid SiO 2 , angle distribution of O Si O and Si O Si in the liquid and solid phases during the simulation considering 169,956 atoms are compared with those of Munetoh et al. [40] and others, and are highlighted as the major limitations of the results of Munetoh et al. [40] and others, and are shown as the superiority of the present simulation results. Details of the bond density of Si Si, Si O, and O O at the liquid and solid phases with bond distance are described. Details of the phase transformation of SiO 2 glass are described with the help of graphical representations. The effects of pressure and temperature on the physical and chemical properties of SiO 2 (α-quartz) are described with the graphical results. Due to high pressure α-quartz is converted into coesite which is discussed.