MD plus QM calculations of the OH vibrational stretching band in an aqueous aluminium(III) chloride solution
2002 (English)In: Journal of Molecular Liquids, ISSN 0167-7322, Vol. sep-98, 367-380 p.Article in journal (Refereed) Published
The OH stretching vibrational band has been calculated by an 'MD+QM' approach for the water molecules in the first hydration shell of the Al3+ ion in a dilute AlCl3 aqueous solution. Molecular Dynamics-generated geometrical snapshots provided the molecular positions, which were subsequently used in ab initio calculations of charge-embedded ion-water clusters at the HF and B3LYP levels. The ion-water clusters which were treated quantum-mechanically were Al3+(H2O)(6)(H2O)(x) (x=2 or 3), where a few water molecules from the second hydration shell were included. 60 oscillators were selected from the MD dumps, and anharmonic vibrational frequencies were computed from the ab initio-generated potential energy curves. Density-of-states bands as well as infrared-intensity-weighted bands are presented. Our average frequency downshift is only 60% of the experimental downshift. Further refinement of the method will concentrate on the description of the remaining part of the second, and the third, hydration shells.
Place, publisher, year, edition, pages
2002. Vol. sep-98, 367-380 p.
molecular-dynamics simulations, liquid water, monte-carlo, ab-initio, aluminum(iii), ice
IdentifiersURN: urn:nbn:se:kth:diva-21506ISI: 000175335100029OAI: oai:DiVA.org:kth-21506DiVA: diva2:340204
QC 201005252010-08-102010-08-10Bibliographically approved