Ab initio molecular dynamics simulations of molten Al$_{1-x}$Si$_{x}$ alloys*

First-principles molecular dynamics simulations have been performed to study the structure and dynamics of molten Al$_{1-x}$Si$_{x}$ alloys over a range of alloy compositions and temperatures. Employing an efficient real-space density functional method coupled with a subspace filtering algorithm, we were able to perform simulations on large systems by avoiding explicit eigenvalue calculations. The calculated static structure factors show excellent agreement with data from X-ray diffraction experiments. The composition and temperature dependence of the simulated microstructure and atomic diffusivity will also be discussed.