Improved simulation method for the calculation of the elastic constants of crystalline and amorphous systems using strain fluctuations

In this paper, a method is proposed for calculating the elastic constants of arbitrarily soft or stiff systems using strain fluctuations. For stiff materials, for example, strain fluctuations may be enhanced by appropriate choice of elastic constants for the bath. Example calculations of the isothermal elastic constants of the nearest-neighbor Lennard-Jones fcc crystal demonstrate improved convergence properties over standard techniques. Elastic constants for a model amorphous polymer system are also presented.