| 1. |
- Pejov, L., et al.
(författare)
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MD plus QM calculations of the OH vibrational stretching band in an aqueous aluminium(III) chloride solution
- 2002
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Ingår i: Journal of Molecular Liquids. - 0167-7322 .- 1873-3166. ; sep-98, s. 367-380
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 2. |
- Rönne, Cecilie, et al.
(författare)
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Low frequency spectroscopy of liquid water using THz-time domain spectroscopy.
- 2002
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Ingår i: Journal of Molecular Liquids. - 0167-7322. ; 101:1-3, s. 199-218
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Tidskriftsartikel (refereegranskat)abstract
- In this paper we present an investigation of the dielectric response of H2O(1) and D2O(1) as a function of temperature from a supercooled state to near the boiling point. The data are obtained using THz-time domain spectroscopy, and covers the frequency range from 0 1-2 THz corresponding to 3 to 66 cm(-1). Before presenting the experimental results, we give a short introduction to some of the properties of liquid water, in particular the inter- and intramolecular motions responsible for the low frequency spectra, and brief introduction to the THz-time domain technique and its application as reflection spectroscopy is given. We also address recent theoretical and experimental contributions to the ongoing discussion regarding the microscopic interpretation of the low frequency modes of liquid water. (C) 2002 Elsevier Science B.V. All rights reserved.
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