uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Proton-transfer dynamics in the (HCO3-)(2) dimer of KHCO3 from Car-Parrinello and path-integrals molecular dynamics calculations
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
2010 (English)In: Acta Crystallographica Section B: Structural Science, ISSN 0108-7681, E-ISSN 1600-5740, Vol. 66, 222-228 p.Article in journal (Refereed) Published
Abstract [en]

The proton motion in the (HCO3-)(2) dimer of KHCO3 at 298 K has been studied with Car-Parrinello molecular dynamics (CPMD) and path-integrals molecular dynamics (PIMD) simulations. According to earlier neutron diffraction studies at 298 K hydrogen is disordered and occupies two positions with an occupancy ratio of 0.804/0.196. A simulation with only one unit cell is not sufficient to reproduce the disorder of the protons found in the experiments. The CPMD results with four cells, 0.783/0.217, are in close agreement with experiment. The motion of the two protons along the O center dot center dot center dot O bridge is highly correlated inside one dimer, but strongly uncoupled between different dimers. The present results support a mechanism for the disorder which involves proton transfer from donor to acceptor and not orientational disordering of the entire dimer. The question of simultaneous or successive proton transfer in the two hydrogen bonds in the dimer remains unanswered. During the simulation situations with almost simultaneous proton transfer with a time gap of around 1 fs were observed, as well as successive processes where first one proton is transferred and then the second one with a time gap of around 20 fs. The calculated vibrational spectrum is in good agreement with the experimental IR spectrum, but a slightly different assignment of the bands is indicated by the present simulations.

Place, publisher, year, edition, pages
2010. Vol. 66, 222-228 p.
Keyword [en]
Potassium hydrogen carbonate, inelastic neutron-scattering, formic-acid dimer, canonical ensemble
National Category
Inorganic Chemistry
Research subject
Chemistry with specialization in Inorganic Chemistry
URN: urn:nbn:se:uu:diva-139708DOI: 10.1107/S0108768110002314ISI: 000275648800013OAI: oai:DiVA.org:uu-139708DiVA: diva2:381904
Available from: 2010-12-29 Created: 2010-12-29 Last updated: 2010-12-29Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text
By organisation
Structural Chemistry
In the same journal
Acta Crystallographica Section B: Structural Science
Inorganic Chemistry

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 131 hits
ReferencesLink to record
Permanent link

Direct link