Structure, spectroscopy and dynamics of layered H2O and CO2 ices

Physical Chemistry Chemical Physics
By: , and 

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Abstract

Molecular dynamics simulations of structural, spectroscopic and dynamical properties of mixed water–carbon dioxide (H2O–CO2) ices are discussed over temperature ranges relevant to atmospheric and astrophysical conditions. The simulations employ multipolar force fields to represent electrostatic interactions which are essential for spectroscopic and dynamical investigations. It is found that at the water/CO2 interface the water surface acts as a template for the CO2 component. The rotational reorientation times in both bulk phases agree well with experimental observations. A pronounced temperature effect on the CO2 reorientation time is observed between 100 K and 200 K. At the interface, water reorientation times are nearly twice as long compared to water in the bulk. The spectroscopy of such ices is rich in the far-infrared region of the spectrum and can be related to translational and rotational modes. Furthermore, spectroscopic signatures mediated across the water/CO2 interface are found in this frequency range (around 440 cm−1). These results will be particularly important for new airborne experiments such as planned for SOFIA.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Structure, spectroscopy and dynamics of layered H2O and CO2 ices
Series title Physical Chemistry Chemical Physics
DOI 10.1039/C2CP41904A
Volume 14
Issue 44
Year Published 2012
Language English
Publisher The Royal Society of Chemistry (Cambridge)
Description 11 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Physical Chemistry Chemical Physics
First page 15464
Last page 15474