Tension and stiffness of the hard sphere crystal-fluid interface
  A combination of fundamental measure density functional theory and Monte Carlo computer simulation is used to determine the orientation-resolved interfacial tension and stiffness for the equilibrium hard-sphere crystal-fluid interface. Microscopic density functional theory is in quantitative agreement with simulations and predicts a tension of 0.66 kT/\sigma^2 with a small anisotropy of about 0.025 kT and stiffnesses with e.g. 0.53 kT/\sigma^2 for the (001) orientation and 1.03 kT/\sigma^2 for the (111) orientation. Here kT is denoting the thermal energy and \sigma the hard sphere diameter. We compare our results with existing experimental findings. 
Andreas H\"artel, Martin Oettel, Roberto E. Rozas, Stefan U. Egelhaaf,   J\"urgen Horbach, and Hartmut L\"owen
cond-mat.soft