Molecular dynamics by the Backward‐Euler method

Abstract This paper introduces a new computational method for molecular dynamics. The method combines the Backward‐Euler scheme for the solution of stiff differential equations with a Langevin‐equation approach to the establishment of thermal equilibrium. The method allows the user to choose a cutoff frequency ω c . Vibrational modes with frequencies below ω c will be fully excited (receive a mean energy of kT per mode), while modes with frequencies greater than ω c will be effectively frozen by the method. By setting ω c = kT/h , one can obtain reasonable agreement with the quantum‐mechanical energy distribution among the various modes, despite the classical character of the computation.