A reference implementation of the adaptive resolution scheme in ESPResSo

We review the adaptive resolution scheme (AdResS) from a technical perspective and collect arguments from several years of research, which culminates into the implementation of AdResS into the open-source package ESPResSo. This flexible implementation allows us to repeat all previous AdResS simulations with one program. We test this reference implementation and resimulate some results of the well-studied tetrahedral fluid from various previous studies to show the functionality of the package.