PyRETIS is a Python library for rare event molecular simulations with emphasis on methods based on transition interface sampling and replica exchange transition interface sampling.

PyRETIS is open source, easy to use and can be interfaced with other simulation packages such as GROMACS or CP2K.

You can use the PyRETIS library to set up tailored simulations or you can use a Python flavored input file to run different kinds of path sampling simulations. Please see the user guide for information about the usage and how to obtain and install PyRETIS.