  A method for the calculation of elastic constants in the NVT ensamble, using
molecular dynamics (MD) simulation with a realistic many-body
embedded-atom-model (EAM) potential, is studied in detail. It is shown that in
such NVT MD simulations, the evaluation of elastic constants is robust and
accurate, as it gives the elastic tensor in a single simulation which converges
using a small number of time steps and particles. These results highlight the
applicability of this method in: (i) the calculation of local elastic constants
of non-homogeneous crystalline materials and (ii) in the calibration of
interatomic potentials, as a fast and accurate alternative to the common method
of explicit deformation, which requires a set of consistent simulations at
different conditions. The method is demonstrated for the calculation of the
elastic constants of copper in the temperature range of 0-1000K, and results
agree with the target values used for the potential calibration. The various
contributions to the values of the elastic constants, namely, the Born, stress
fluctuation and ideal gas terms, are studied as a function of temperature.
