A New Molecular-Dynamics Approach for Fully Relaxed Crystals at Constant Pressure

A new molecular-dynamics method at constant pressure has been proposed. As the three edge vectors of a crystal cell as well as the position vectors of all particles are taken as independent variables, this method allows the crystal to relax fully. Furthermore, the effect of pressure on the crystal structure is explicitly given in this approach. As an example, the evolution process of cobalt from a structure far from the final one to the ideal hexagonal close packing structure was given.