where 𝑟 6@ is the distance between i-th ovoid and j-th counterpart. The 𝜀 6@ and 𝜎 6@ are the geometric means of the well depth or the van der Waals distance of i-th and j-th particles, respectively. For normal atoms, homonuclear parameters of the well depth and the van der Waals distance in the UFF scheme were adopted. For the ovoid, these parameters were calculated as follows. Apparently, the van der Waals distance is correlated with the van der Waals radius. Assuming that the distance where the homonuclear LJ potential becomes zero is close to the diameter of the corresponding atom (Figure ), this correlation can be formulated as follows: