DFT-computed νFeN/νNO correlations for (ImH)Fe(III)NO-P-X, without (blue points and line, as in Fig. 9), and with a distal ImH that is rotated to allowed to interact with NNO (black points and lines). In the latter case, the correlation is negative for electron-donating substituents, but positive for electron-withdrawing substituents, as the ImH approaches NNO, and Fe-N-O angle is lowered. A parallel positive correlation is obtained if bending is induced by constraining the Fe-N-O angle (green triangles and line).