The differences between the Grimme-type dispersion corrections (D2 and D3) are subtle, and can have many competing effects. While the GD3 scheme adds an additional energy term (R 8 ) (Equation ), it does not always bind more strongly than GD2 (see Figures and). The dispersion coefficients are different between GD2 and GD3, but, so are the damping functions used to force the dispersion correction to 0 at small atomic distances.