This package provides methods for performing free energy perturbation simulations with soft-core pair potentials in LAMMPS. See the doc page for the fix adapt/fep command to get started. There are example scripts for using this package in examples/USER/fep. There are auxiliary tools for using this package in tools/fep. The person who created this package is Agilio Padua at Université Blaise Pascal Clermont-Ferrand (agilio.padua at univ-bpclermont.fr) Contact him directly if you have questions. Pair style morse/soft was contributed by Stefan Paquay, s.paquay at tue.nl Applied Physics/Theory of Polymers and Soft Matter, Eindhoven University of Technology (TU/e), The Netherlands Contact him in case of problems with this pair style. Pair styles lj/class2/soft were contributed by Evangelos Voyiatzis at Technical University of Darmstadt (e.voyiatzis at theo.chemie.tu-darmstadt.de) Contact him in case of problems with these pair styles.