OpenMM does not offer any inbuilt alchemical methods and as such there exist a number of programs which extend OpenMM, allowing systems to be manipulated alchemically and perform alchemical calculations. One such program, used in this work, is OpenMMTools 0.19.0 . OpenMMTools can take as input a standard OpenMM system, defined with some potentials, and transforms this system into an alchemical one, where the potentials are controlled by the λ parameter. The scaling of (LJ) interactions was performed with a softcore potential using the functional form of equation 13 presented in the work of Pham et al. with parameters: α = 0.5, a = 1, b = 1 and c = 6, the default parameters used by OpenMMTools. Electrostatic interactions are scaled linearly without a soft-core potential.