Correlating the calculated and the experimentally observed absolute binding free energies obtained by the PDLD/S-LRA/β, the LRA/β and the LIE methods using default values i.e. same β (graphs a, c and d) and fitted values i.e. variable β (graphs b, d, and e). Note that in PDLD/S-LRA/β approach, we used ε p = 20 for the charged ligands.