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

The charge density of urea from synchrotron diffraction data.

Henrik Birkedal1, Dennis Madsen, Ragnvald H Mathiesen

  • 1Laboratory of Crystallography, Swiss Federal Institute of Technology, BSP, CH-1015 Lausanne, Switzerland. hbirkedal@chem.au.dk

Acta Crystallographica. Section A, Foundations of Crystallography
|October 13, 2004
PubMed
Summary

High-precision X-ray diffraction reveals urea

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

The mantis shrimp eye imaged in 3D using 4th generation synchrotron multiscale phase contrast tomography.

Journal of structural biology·2026
Same author

AI-assisted semi-automated segmentation for tooth volume analysis in postmortem CT imaging: evaluation of forensic applicability.

International journal of computerized dentistry·2026
Same author

Interfaces at the nano scale: general discussion.

Faraday discussions·2025
Same author

Crystal nucleation in biominerals: general discussion.

Faraday discussions·2025
Same author

Enamel-like stiffness achieved by poorly oriented nanocrystals in the capping tissue of Mexican beaded lizard osteoderms.

Acta biomaterialia·2025
Same author

Biomineral displays systematic spatially varying crystallographic properties in fibrolamellar bone as revealed by position resolved X-ray diffraction.

Faraday discussions·2025

Area of Science:

  • Crystallography
  • Quantum Chemistry
  • Materials Science

Background:

  • Accurate charge density distribution is crucial for understanding chemical bonding.
  • Previous studies on urea's electronic structure have shown discrepancies between experimental and theoretical data.

Purpose of the Study:

  • To precisely determine the charge density distribution of urea using advanced experimental techniques.
  • To compare experimental findings with theoretical calculations and validate computational methods.
  • To investigate the thermal expansion properties of urea.

Main Methods:

  • Single-crystal synchrotron X-ray diffraction at 123 K with unprecedented resolution (1.44 Å⁻¹).
  • Multipole model refinement including hexadecapoles and quadrupoles.

Related Experiment Videos

  • Periodic Hartree-Fock calculations for ab initio comparison.
  • Powder diffraction for thermal expansion analysis.

    • Main Results:

    • High-resolution data enabled detailed charge density analysis.
    • Experimental C-O bond properties align with previous findings but differ from ab initio calculations.
    • Calculated atomic charges significantly exceed experimental values.
    • Solid-state urea exhibits a dipole moment enhancement of ~1.5 D compared to gas/solution phases.
    • Anisotropic strain increases with decreasing temperature.

    Conclusions:

    • Experimental charge density data provide new benchmarks for theoretical calculations.
    • Theoretical models require more flexible basis sets for accurate C-O bond description in urea.
    • Urea's solid-state dipole moment is enhanced due to intermolecular interactions.
    • Urea displays anisotropic thermal expansion, with strain increasing at lower temperatures.