Nuclear momentum distribution in solid and liquid HF from ab initio calculation.
1Rutherford Appleton Laboratory, ISIS Facility, Chilton OX11 0QX, United Kingdom. matthew.krzystyniak@stfc.ac.uk
The Journal of Chemical Physics
|October 19, 2010
Summary
We calculated nuclear momentum distributions for liquid and solid hydrogen fluoride using density functional theory. Theoretical results closely matched experimental neutron scattering data, especially for the liquid phase.
Area of Science:
- Theoretical chemistry
- Condensed matter physics
- Quantum mechanics
Background:
- Nuclear momentum distribution provides insights into molecular and crystal dynamics.
- Hydrogen fluoride exists in both liquid and solid phases with distinct properties.
- Density functional theory (DFT) is a powerful tool for electronic structure calculations.
Purpose of the Study:
- To calculate the nuclear momentum distribution of liquid and solid hydrogen fluoride.
- To compare theoretical predictions with experimental neutron scattering data.
- To investigate the effects of hydrogen bonding on nuclear momentum in solid hydrogen fluoride.
Main Methods:
- Utilized DFT with the Perdew-Burke-Ernzerhof generalized gradient approximation functional.
- Employed atom-centered basis sets for liquid HF and plane-wave basis sets for solid HF.
- Adopted a semiclassical approach for liquid HF and a fully quantum mechanical approach for solid HF.
Main Results:
- Achieved excellent agreement between theoretical and experimental results for liquid hydrogen fluoride.
- Observed a small (4%) overestimation in the solid phase, attributed to proton delocalization.
- Demonstrated the sensitivity of neutron Compton scattering to hydrogen bonding effects.
Conclusions:
- The theoretical model accurately predicts nuclear momentum distribution in liquid hydrogen fluoride.
- Proton delocalization due to hydrogen bonding influences nuclear momentum in solid hydrogen fluoride.
- DFT calculations combined with experimental scattering data offer a comprehensive understanding of hydrogen fluoride systems.
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