Fig. 3.

Decay behavior of the fit coefficients of model 2D and 3D systems. The 2D system is based on a graphite structure, with each site slightly perturbed. The 3D system is based on a diamond structure, slightly perturbed. For each case the target function is the thrice-contracted s function of the vdz basis. The auxiliary basis set is the corresponding basis set for J-matrix fitting. The 2D fit coefficients decay more rapidly than for the linear case, and the 3D coefficients decay far more rapidly still, suggesting strong dimensional dependence.