This directory contains files required to use the USER-PACE package, which provides the pace pair style, an efficient implementation of the Atomic Cluster Expansion potential (ACE). ACE is a methodology for deriving a highly accurate classical potential fit to a large archive of quantum mechanical (DFT) data. This package was written by Yury Lysogorskiy and others at ICAMS, the Interdisciplinary Centre for Advanced Materials Simulation, Ruhr University Bochum, Germany, http://www.icams.de You can type "make lib-pace" from the src directory to see help on how to download and build this library via make commands, or you can do the same thing by typing "python Install.py" from within this directory. More information about the USER-PACE implementation of ACE is available here: https://github.com/ICAMS/lammps-user-pace