To explore the effects of alternative electronic environments, we calculated the coreionization values for the α carbon atom of hexenol and the oxygen atom in hexanoic acid, depicted in the bottom row of Fig. . Both of these molecules feature π bonds involving the atom in question. Note that for hexanoic acid, we investigate the doubly-bound oxygen core-hole ionization, instead of that of the α-carbon. As depicted in Fig. , we observed a convergence of core-ionization energy with an increasing embedding space, similar to the cases mentioned above. However, for hexenol, as shown in Fig. , the deviation when keeping nearest neighbors in the embedding space was 0.1 eV at CC-PCVTZ, slightly higher than its saturated counterpart. This minimal deviation remained constant with an increasing embedding space and only converged when including the entire conjugated system in the embedding space. On the other hand, for the doubly-bound oxygen atom of hexanoic acid, as shown in Fig. , maintaining only the -CO unit in the embedding space resulted in a significant deviation ( > 5 eV, see inset of Fig. ). However, incorporating the next -OH unit, thus including the -COOH unit in the embedding space, reduced the deviation to only 0.06 eV from the non-embedding limit at the CC-PCVTZ basis. Evidently, in this case, atomic orbitals from both oxygen atoms are necessary to construct a qualitatively accurate picture of the oxygen-atom core-hole ionization energy. Adding more nearest neighbor atoms has a minimal effect. The absolute values and deviation table for these two molecules can be found in Table , and S14.