Figure 2

Energy of VdW interactions at various configurations of participating non-bonded and bonded atoms. The distance between the closest non-bonded atoms is 4 Å in all cases, and unity is used as the energy of pairwise interaction of atoms at 4Å distance. If the distance between the closest non-bonded atoms is |r| ≈ 4 Å, all energies presented in the Table change as (4Å/|r|)⁶, approximately, and their ratio does not change essentially. The value γ = 0.15 describes the coupling of oscillations in two atoms connected by a covalent bond of fixed length 1.5 Å (see text for further explanation).