With µ ′ sol fixed, the Adams value is dependent only on the concentration of fragment in the reference solution. It is now intuitive to say that a higher reference solution concentration would lead to more binding in the GCMC region of the protein, as shown in Figure . As explained in the next section, the concentration of fragment which leads to 50% occupancy in a binding site is equivalent to the dissociation constant, K D . We define the corresponding Adams value as B 50 :