Additional theoretical and numerical support for this model were provided later. With the help of recursion relations for the higher-order dispersion coefficients, Eq. ( ) forms the basis of a DFT+D model of the form in Eq. ( ) and consisting of C 6 , C 8 , and C 10 terms, with each C n coefficient reflects the molecular environment. This is the Becke-Johnson XDM approach. Parameters for R vdW ab in Eq. ( ) have been determined for a variety of XC functionals. In the vdW-TS scheme, 51 a relationship analogous to Eq. ( ) is assumed for the effective atomic C 6 coefficients,