Size of the hydrogen bond network in liquid methanol: a quantum cluster equilibrium model with extensive structure search. Issue 15 (12th April 2021)

• Record Type: Journal Article
• Authors: Teh, Soon; Hsu, Po-Jen; Kuo, Jer-Lai
• Is Part Of: Physical chemistry chemical physics. Volume 23:Issue 15(2021)
• Page Start: 9166
• Page End: 9175
• Publication Date: 2021-04-12
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d1cp00427a
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : The dominant cluster size in liquid methanol was explored by quantum cluster equilibrium theory associated with an extensively searched structure database. Abstract : Studies have debated what is a favorable cluster size in liquid methanol. Applications of the quantum cluster equilibrium (QCE) model on a limited set of cluster structures have demonstrated the dominance of cyclic hexamers in liquid methanol. In this study, we examined the aforementioned question by integrating our implementation of QCE with a molecular-dynamics-based structural searching scheme. QCE simulations were performed using a database comprising extensively searched stable conformers of (MeOH) n for n = 2–14, which were optimized by B3LYP/6-31+G(d, p) with and without the dispersion correction. Our analysis indicated that an octamer structure can contribute significantly to cluster probability. By reoptimizing selected conformers with high probability at the MP2 level, we found that the aforementioned octamer became the dominant species due to favorable vibrational free energy, which was attributed to modes of intermolecular vibration.