Assessment and optimization of the fast inertial relaxation engine (fire) for energy minimization in atomistic simulations and its implementation in lammps

•An improved version of the FIRE algorithm is now implemented in LAMMPS.•The widely used FIRE algorithm requires a symplectic time integration scheme.•Default parameters are recommended to ensure optimal performance.•Its application is shown and discussed using multiple examples from materials science. In atomistic simulations, pseudo-dynamical relaxation schemes often exhibit better performance and accuracy in finding local minima than line-search-based descent algorithms like steepest descent or conjugate gradient. Here, an improved version of the fast inertial relaxation engine (fire ) and its implementation within the open-source atomistic simulation code lammps is presented. It is shown that the correct choice of time integration scheme and minimization parameters is crucial for the performance of fire.