Novel crystal structures for lithium-silicon alloy predicted by minima hopping method

We present an ab initio study of the phase diagram of the Li-Si binary system using the minima hopping method for global structural prediction. By varying the chemical composition we obtained the theoretical convex hull, whose vertices are constituted by three stoichiometries, two of them have not been reported previously. Additionally, we find five more unreported meta-stable structures, which are slightly higher in energy with respect to the convex hull line. We further characterize all these obtained phases by calculating their electronic, mechanical, and dynamical properties. Finally, and as this class of systems is viewed with interest for possible anodes in lithium batteries, we also report the potential-composition curve and compare it with available experimental measurements.