We have performed molecular dynamics calculations for a crystalline system in equilibrium to show that by using a fluctuation formula involving the internal stress tensor it is possible to calculate the elastic constants at the ambient temperature with ease and accuracy. The method also allows one to calculate the elastic constants when the system is subjected to an arbitrary external stress.

• Received 25 February 1985

DOI:https://doi.org/10.1103/PhysRevB.32.733