ISIS Neutron and Muon Source Data Journal

Anharmonic Vibrations and Non-Adiabatic Effects in LiH and LiD: A Case study Using Neutron Compton Scattering

Abstract: In solid systems, distortions of the longitudinal nuclear-momentum distributions manifest themselves as departures from the Gaussian Approximation. These can be due to either the non-isotropic and/or non-harmonic nature of nuclear-momentum distributions, and these two effects are not easy to disentangle. As the harmonic Born Oppenheimer approximation (BOA) seems to account very well for crystal vibrations in LiH/ LiD at room temperature, a hypothesis can be put forward that ca. 2-3% of observed deviations compared to first-principles predictions should be mainly caused by collisionally induced non-BOA effects and associated anharmonicities. To test this hypothesis, LiH/LiD powders will be measured at temperatures T=10-500 K. Monte-Carlo fitting of these data will be used for a detailed comparison with predictions of harmonic and anharmonic ab initio calculations.

Principal Investigator: Dr Matthew Krzystyniak
Experimenter: Professor Felix Fernandez-Alonso
Experimenter: Dr Selena Richards

DOI: 10.5286/ISIS.E.RB1410047

ISIS Experiment Number: RB1410047

Publisher: STFC ISIS Neutron and Muon Source

Data format: RAW/Nexus
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Data Citation

The recommended format for citing this dataset in a research publication is as:
[author], [date], [title], [publisher], [doi]

For Example:
Dr Matthew Krzystyniak et al; (2014): Anharmonic Vibrations and Non-Adiabatic Effects in LiH and LiD: A Case study Using Neutron Compton Scattering, STFC ISIS Neutron and Muon Source, https://doi.org/10.5286/ISIS.E.RB1410047

Data is released under the CC-BY-4.0 license.