Two versions of NAMD2/3 are used in this work, for CPU and GPU calculations. The alchemical protocol used is the same and so they will be discussed here jointly. The NAMD method uses a soft-core potential to decouple the LJ interactions. This soft-core potential can be expressed in the same form as the OpenMM soft-core using parameters α = 0.5, a = 1, b = 1 and c = 2 these are the default parameters used by NAMD. Electrostatic interactions are decoupled linearly without a soft-core potential. The λ schedule used in the NAMD calculations was a one-step procedure where LJ and electrostatic potentials are scaled simultaneously. Decoupling was used in the NAMD method as this is the method invoked in our original NAMD2 based study of these systems . In this context, decoupling means that when a chemical moiety is "turned off" only the inter molecular interactions are removed.