# Electric Field and Temperature Effects on the Ab Initio Spectroscopy of Liquid Methanol
## 4 Conclusions  
In the current study, by employing state-of-the-art ab initio molecular dynamics (AIMD) simulations, we have reported the IR spectra of liquid methanol under the action of static and homogeneous electric fields with intensities up to 0.30 V/A. Moreover, with the aim of comparing electric-field-induced and temperature-induced effects, we have here also presented IR spectra of liquid methanol at different temperatures, from 240 K up to 350 K. Although some electric-field-induced effects resemble the response of other polar liquids (such as the global contraction of the IR spectrum upon field exposure), it turned out that, contrarily to water, the \"electrofreezing\" phenomenon is unlikely to happen in liquid methanol. Differently from what is observed in liquid water, where the application of a static electric field leads to a more \"ice-like\" structured liquid [47], in neat liquid methanol the effects induced by the field are sharply separated from those produced by a decrease in the temperature. The effects produced by the application of a vector (i.e., the oriented electric field) and those afforded by varying a scalar quantity (i.e., the temperature) on matter are, a priori and by their own nature, deeply different. However, the higher multiplicity and larger percolation degree of the H-bond network present in liquid water with respect to that of methanol significantly mitigates the intrinsic differences carried by an electric field intensity increase and a temperature decrease. In fact, whereas in water the direction imposed by the external field to the dipole vectors can lead to H-bonded solid-like structures, in methanol it can only lead to linear chains of H-bonded molecules all oriented along the field axis and with the hydrophilic heads placed in favor of the field [49; 50], a circumstance preventing the formation of any methanol solid phase. Moreover, here we have shown that the seminal effect produced by the external field is that of decreasing the average  
Figure 8: Intermolecular oxygen–oxygen (**top**), oxygen–hydrogen (**center**), and carbon–oxygen (**bottom**) radial distribution functions (RDFs) in bulk neat methanol at different field strengths and at room temperature (**left**) and in the zero-field case and for different values of the temperature (**right**). number of H-bonds in which a methanol molecule is statistically involved. Additionally to the evidence visible at the atomistic level, the different response of liquid methanol to diverse external thermodynamic variables (electric field and temperature) is manifested from the completely different vibrational response this liquid exhibits in the IR spectra here presented. This way, whilst the electrofreezing phenomenon appears to be possible in water in principle, it is unlikely in methanol. Conceptualization, G.C. ; methodology, G.C. ; software, G.C. ; validation, G.C., S.T. and F.S. ; formal analysis, G.C., S.T. and F.S. ; investigation, G.C., S.T. and F.S. ; resources, J.S. ; data curation, G.C. and S.T. ; writing--original draft preparation, G.C., S.T. and F.S. ; writing--review and editing, G.  
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