An investigation of the local structure and dynamic properties of undercooled liquid silicon using the orbital-free ab-initio molecular dynamics method

Abstract

We present results for the static and dynamic structural properties of undercooled liquid Si, at several temperatures between 1550 K and 1100 K, obtained through orbital-free ab-initio molecular dynamics simulations. The local bond angle distributions show a modest increase in the tetrahedral order upon decreasing the temperature. We also analyze the variation of several dynamic magnitudes and transport properties with temperature, showing a tendency to sustain shear waves for some wavevectors as undercooling is deepened. We compare our orbital-free ab-initio results with the limited experimental data available, as well as with results of other ab-initio simulations.