MOLECULAR-DYNAMICS STUDY OF LI2SIS3 GLASS

Molecular dynamics simulation has been carried out for highly conducti ng Li2SiS3 glass at temperatures ranging from 300-1800 K in order to i nvestigate the glass structure and dynamical behaviour of the mobile i ons Li+. The glass transition temperature obtained from the change in energy and diffusion constant D of Li+ as temperature is lowered occur s around 750 K. Silicon is predominantly pentacoordinated to sulphur a toms at an average distance 2.19 Angstrom, the geometry around Si bein g approximately square pyramidal. The glass matrix shows little change with temperature. Room temperature value of diffusion constant (D) of Li+ is 3.53 x 10(-10) m(2) s(-1). Lithium ions are surrounded by four sulphur atoms, Li-S distance being 2.61 Angstrom.