Figure 5

Löwdin population analysis of CH₃OH₂ ⁺ and CH₃O⁻ in the gas phase (a,b) and in the liquid phase (c,d) without (a,c) and with an external electric field at a strength of \(0.60\) V/Å (b,d). The blue arrow shows the field orientation. The coloring method follows the atomic electron populations shown in Table S1. In particular, the atomic population values relative to the expected ideal atomic valence population (i.e., \(6\) for the oxygen, \(4\) for the carbon, and \(1\) for the hydrogen atoms) are plotted. Deep blue coloration indicates a strong positive value with respect to the expected ideal valence population; deep red coloration illustrates a strong negative value with respect to the expected valence population; white coloration stems from estimated values very close to the standard ideal electronic population of each atomic species.