Crystal nucleation in covalent and ionic systems
Dr. Chantal Valeriani (University of Edinburgh)

Most liquids can be cooled below their equilibrium freezing point before crystals start to form in the bulk. Crystal growth can only proceed when, due to some rare fluctuation, one or more micro-crystallites exceed a critical size (the "critical nucleus"). This process is called homogeneous nucleation.

At moderate super-cooling, nucleation does not happen spontaneously, and it is too slow to be studied with ``brute-force' Molecular Dynamics or Monte Carlo simulations. Therefore, novel "rare event techniques" are needed to bridge the time-scale gap between microscopic dynamics and the time it takes for a (rare) nucleation event to take place.

In my talk, I will focus on numerical simulation results of homogeneous nucleation of two systems of our interest: diamond nucleation from molten carbon and crystal nucleation of a Yukawa binary mixture from its melt.