Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

New ortho-para conversion mechanism in dense solid hydrogen.

M A Strzhemechny1, R J Hemley

  • 1Geophysical Laboratory and Center for High Pressure Research, Carnegie Institution of Washington, 5251 Broad Branch Road, NW, Washington, D.C. 20015, USA.

Physical Review Letters
|January 3, 2001
PubMed
Summary

High pressure alters solid hydrogen

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Creating superconductivity in WB<sub>2</sub> through pressure-induced metastable planar defects.

Nature communications·2022
Same author

Ordering of hydrogen bonds in high-pressure low-temperature H2O.

Physical review letters·2005
Same author

Structural transformation of molecular nitrogen to a single-bonded atomic state at high pressures.

The Journal of chemical physics·2005
Same author

Formation and structure of a dense octahedral glass.

Physical review letters·2004
Same author

Polymerization of nitrogen in sodium azide.

The Journal of chemical physics·2004
Same author

Nuclear inelastic x-ray scattering of FeO to 48 GPa.

Physical review letters·2001

Area of Science:

  • Condensed matter physics
  • Quantum chemistry
  • High-pressure science

Background:

  • Ortho-para conversion in solid hydrogen is crucial for understanding its quantum states.
  • Existing models of conversion mechanisms are based on ambient pressure conditions.
  • High-pressure studies reveal deviations from established conversion pathways.

Purpose of the Study:

  • To investigate the mechanism of ortho-para conversion in solid hydrogen under high pressure.
  • To identify novel conversion pathways beyond nuclear spin-spin interactions.
  • To elucidate the role of pressure in modifying the conversion process.

Main Methods:

  • Analysis of recent experimental measurements of solid H(2) conversion rates up to 58 GPa.
  • Theoretical modeling to identify the dominant coupling mechanism.
  • Investigating the influence of pressure-induced electronic structure changes.

Main Results:

  • A new ortho-para conversion mechanism involving electric quadrupole-quadrupole interactions was identified.
  • This new mechanism dominates over nuclear spin-spin interactions at high pressures.
  • Conversion energy significantly decreases with increasing pressure due to gap closing.

Conclusions:

  • The ortho-para conversion mechanism in solid hydrogen fundamentally changes at high pressures (up to 58 GPa).
  • Electric quadrupole-quadrupole coupling, enhanced by compression, becomes the primary driver.
  • Pressure-induced changes in electronic structure and energy gaps are key to this new mechanism.

Related Experiment Videos