English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Displacements of atoms and molecules away from lattice sites in helium andparahydrogen solids at low temperature have been studied by means of QuantumMonte Carlo simulations. In the bcc phases of He-3 and He-4, atomicdisplacements are largely quantum-mechanical in character, even at melting. Thecomputed Lindemann ratio at melting is found to be in good agreement withexperimental results for He-4. Unlike the case of helium, in solid parahydrogenthere exists near melting a significant thermal contribution to molecularvibrations, accounting for roughly half of the total effect. Although theLindemann ratio at melting is in quantitative agreement with experiment,computed molecular mean square fluctuations feature a clear temperaturedependence, in disagreement with recent experimental observations.

Atomic displacements in quantum crystals