In thermal motion, the instantaneous stresses and strains are correlated throughout phase space—a fluctuation equation for the elastic constants is presented here that takes advantage of this fact. Results obtained with a nearest-neighbor Lennard-Jones fcc crystal indicate that the equation is considerably more efficient than the Parrinello-Rahman fluctuation formula. © 1996 The American Physical Society.

• Received 1 September 1995

DOI:https://doi.org/10.1103/PhysRevB.54.1