Disentangling Coupling Effects in the Infrared Spectra of Liquid Water.
J Phys Chem B
; 122(47): 10754-10761, 2018 11 29.
Article
em En
| MEDLINE
| ID: mdl-30403350
ABSTRACT
A quantitative characterization of intermolecular and intramolecular couplings that modulate the OH-stretch vibrational band in liquid water has so far remained elusive. Here, we take up this challenge by combining the centroid molecular dynamics formalism, which accounts for nuclear quantum effects, with the MB-pol potential energy function, which accurately reproduces the properties of water across all phases, to model the infrared (IR) spectra of various isotopic water solutions with different levels of vibrational couplings, including those that cannot be probed experimentally. Analysis of the different IR OH-stretch line shapes provides direct evidence for the partially quantum-mechanical nature of hydrogen bonds in liquid water, which is emphasized by synergistic effects associated with intermolecular coupling and many-body electrostatic interactions. Furthermore, we quantitatively demonstrate that intramolecular coupling, which results in Fermi resonances due to the mixing between HOH-bend overtones and OH-stretch fundamentals, is responsible for the shoulder located at â¼3250 cm-1 of the IR OH-stretch band of liquid water.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
J Phys Chem B
Assunto da revista:
QUIMICA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Estados Unidos