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Oxygen-oxygen correlations in liquid water: addressing the discrepancy between diffraction and extended x-ray
Kjartan Thor Wikfeldt1, Mikael Leetmaa, Amber Mace
1FYSIKUM, AlbaNova University Center, Stockholm University, SE-106 91 Stockholm, Sweden.
The Journal of Chemical Physics
|March 18, 2010
Summary
Reconciling X-ray diffraction and EXAFS data for liquid water reveals that nearly linear hydrogen bonds and structural disorder are key. This study introduces a new modeling technique to accurately describe water
Area of Science:
- Physical Chemistry
- Materials Science
- Computational Chemistry
Background:
- The oxygen-oxygen pair-correlation function (O-O PCF) is crucial for understanding liquid water structure.
- Discrepancies exist between diffraction and EXAFS regarding the O-O PCF's first peak.
Purpose of the Study:
- Investigate the discrepancy between diffraction and EXAFS data for liquid water.
- Develop a novel method to reconcile these differing structural insights.
Main Methods:
- Utilized a new SpecSwap-RMC technique, combining reverse Monte Carlo with multiple data sets.
- Incorporated many-body photoelectron scattering focusing effects from nearly linear hydrogen bonds.
- Performed real-space multiple-scattering calculations on water clusters.
Main Results:
- Reconciled EXAFS and diffraction data by including photoelectron scattering effects.
- Demonstrated that nearly linear hydrogen bonds and structural disorder are essential for simultaneous fitting.
- Showed the SpecSwap-RMC method's utility for modeling disordered materials.
Conclusions:
- The SpecSwap-RMC method successfully integrates EXAFS and diffraction data for liquid water.
- Accurate modeling requires accounting for both hydrogen bond linearity and local structural disorder.
- This approach is valuable for analyzing complex, disordered materials.
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