Figure 2.

The interaction terms implemented in AutoDock Vina. d is the distance between two atoms, a₁ and a₂. d_opt(a₁, a₂) is the optimal distance between atoms (the sum of the van der Waals radii). d_diff (a₁, a₂) is d − d_opt (a₁, a₂). o, w, x, b, and q are parameters that are varied as shown in Table 1 to produce different terms. o offsets the optimal position of the term. w specifies the width of a Gaussian. x is the exponent of the electrostatic term. b specifies where the piecewise linear terms become zero. q determines to what extent the desolvation term is charge dependent.