  Recently a non-empirical stochastic walker algorithm has been developed to
search for the minimum-energy escape paths (MEP) from the minima of the
potential surface [J. Phys. Soc. Jpn. 87, 063801 (2018); Physica A, 528, 121481
(2019)]. This method is based on the Master equation for the distribution
function of the atomic configuration which has a nature to seek the MEP up
along the valley of the potential surface. This paper introduces AtomREM
(Atomistic Rare Event Manager), which is an MPI parallelized solver program
package for executing this method, which yields minimum energy reaction
pathways in terms of the microscopic evolution of atomic positions. It is
open-source and released under the GNU General Public License (GPL). AtomREM
interfaces with the LAMMPS Molecular Dynamics Simulator as a library of
versatile potential functions for application to various systems. Examples of
the applications to molecular and solid systems are presented.
