which is also proportional to x(0) H and independent of the C environment. This explains how the perturbational replicates can reduce to the linear analogies found at the first order perturbation, and how similar changes whether on alkane or alcohol are colinear. As Table shows, we obtain greater accuracy with greater perturbations on the neighborhood embedding replicates. Of course, including the higher order corrections, will integrate long-range effects and provide a more fine-tuned reaction vector that will explain deviations from the exact constant vector. Fig. The accuracy of perturbational replicates across the 2000 molecule test set for gas-phase 13 C-NMR and