Revisit of interfacial free energy of the hard sphere system near hard wall

We propose a simple Monte Carlo method to calculate the interfacial free energy between the substrate and the material. Using this method we investigate the interfacial free energys of the hard sphere fluid and solid phases near a smooth hard wall. According to the obtained interfacial free energys of the coexisting fluid and solid phases and the Young equation we are able to determine the contact angle with high accuracy, cos$\theta$ = 1:010(31), which indicates that a smooth hard wall can be wetted completely by the hard sphere crystal at the interface between the wall and the hard sphere fluid.