where the outer summation is carried out over all selected A•••B contacts, and w(A•••B) is a weight defined as the root square of number of LoS contacts shorter than Dmax. Because the contact shielding depends on vdW radii, the RvdW values obtained at the first step were used to recalculate the contact shielding parameters and determine the Dmax values for all atom pairs. This procedure was repeated iteratively until a convergence of 0.001 Å was reached for all RvdW.