Welcome to this new special issue of Molecular Simulation on ‘Free Energy Simulations’, Volume III! Following up on the tremendous success of Volumes I and II of the ‘Free Energy Simulations’ series, and given the terrific feedback we received over the past year, we set on to develop Volume III of this very special series. In this issue, we selected ten papers discussing free energy simulations, their methodological underpinnings and applications to chemistry, biology, physics, materials science and chemical engineering. Once again, we are extremely grateful to Professor Martin Karplus, 2013 Nobel Prize in Chemistry, for participating to this adventure, for taking the time to help us assemble such a great special issue and for his patience and exceptional knowledge throughout the entire process. We are also very much indebted to our authors for this exciting and very special issue! We hope that this volume of ‘Free Energy Simulations’ will continue to stimulate reflection and discussion between researchers in the field of Molecular Simulation.
Finally, I would like to thank the Editor-In-Chief of Molecular Simulation, Dr. Nick Quirke, our Production Editor, Irene Legaspi and all the staff at Molecular Simulation. We hope you will enjoy this special issue of Molecular Simulation.