Different structures give similar vibrational spectra: The case of OH- in aqueous solution
2013 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 138, no 6, 064503- p.Article in journal (Refereed) Published
We have calculated the anharmonic OH-(aq) vibrational spectrum in aqueous solution with a "classical Monte Carlo simulation + QM/MM + vibrational" sequential approach. A new interaction model was used in the Monte Carlo simulations: a modified version of the charged-ring hydroxide-water model from the literature. This spectrum is compared with experiment and with a spectrum based on CPMD-generated structures, and the hydration structures and H-bonding for the two models are compared. We find that: (i) the solvent-induced frequency shift as well as the absolute OH- frequency are in good agreement with experiment using the two models; (ii) the Raman and IR bands are very similar, in agreement with experiment; (iii) the hydration structure and H-bonding around the ion are very different with the two ion-water interaction models (charged-ring and CPMD); (iv) a cancellation effect between different regions of the hydration shell makes the total spectra similar for the two interaction models, although their hydration structures are different; (v) the net OH- frequency shift is a blueshift of about + 80 cm(-1) with respect to frequency of the gas-phase ion.
Place, publisher, year, edition, pages
2013. Vol. 138, no 6, 064503- p.
Quantum-Mechanics, Basic Solutions, Hydroxide Ion, Ab-Initio, Water, Dynamics, Density
Chemical Sciences Physical Sciences
IdentifiersURN: urn:nbn:se:kth:diva-119737DOI: 10.1063/1.4775589ISI: 000315054400025ScopusID: 2-s2.0-84874286392OAI: oai:DiVA.org:kth-119737DiVA: diva2:612575
FunderSwedish Research CouncilKnut and Alice Wallenberg Foundation
QC 201303222013-03-222013-03-212013-03-22Bibliographically approved