Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Search research articles

Related Experiment Videos

Statistical dynamical direct methods. I. The effective kinematical approximation

Hu¹, Chukhovskii, Marks

¹Northwestern University, Evanston, IL 60208-3108, USA.

Acta Crystallographica. Section A, Foundations of Crystallography

|September 1, 2000

Summary

This summary is machine-generated.

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

A bulk electrolysis Raman spectroelectrochemical cell using a rotating electrode

Analytical chemistry·2000

Same author

Fluorescence Excitation Spectrum of a (2)Pi(3/2)-(2)Pi(3/2) Transition of NiF.

Journal of molecular spectroscopy·2000

Same author

Changes of reliability and efficiency of micronucleus bioassay in Vicia faba after exposure to metal contamination for several generations.

Environmental and experimental botany·2000

Same author

Probability distribution of the four-phase structure invariants of isomorphously related structure factors and its applications.

Acta crystallographica. Section A, Foundations of crystallography·2000

Same author

Tris(ethylenediamine-N,N')cobalt(III) oxalate perchlorate dihydrate

Acta crystallographica. Section C, Crystal structure communications·2000

Same author

Automated identification of symmetry in CBED patterns: a genetic approach

Ultramicroscopy·2000

Same journal

Report of the Executive Committee for 2006.

Acta crystallographica. Section A, Foundations of crystallography·2020

Same journal

Spin line groups.

Acta crystallographica. Section A, Foundations of crystallography·2013

Same journal

Distribution rules of systematic absences on the Conway topograph and their application to powder auto-indexing.

Acta crystallographica. Section A, Foundations of crystallography·2013

Same journal

Platonic solids generate their four-dimensional analogues.

Acta crystallographica. Section A, Foundations of crystallography·2013

Same journal

C70, C80, C90 and carbon nanotubes by breaking of the icosahedral symmetry of C60.

Acta crystallographica. Section A, Foundations of crystallography·2013

Same journal

Comparative study of X-ray charge-density data on CoSb3.

Acta crystallographica. Section A, Foundations of crystallography·2013

See all related articles

The kinematical approximation in electron diffraction is surprisingly effective for determining atomic structures, even beyond thin samples. This study explains how phase distributions maintain a narrow, effectively kinematical nature, validating direct methods.

Area of Science:

Crystallography
Materials Science
Physics

Background:

The kinematical approximation is generally considered inadequate for transmission electron diffraction.
Recent successes in atomic structure determination using direct methods challenge this notion.

Purpose of the Study:

To investigate the discrepancy between the poor theoretical applicability of the kinematical approximation and its practical success in electron diffraction.
To elucidate the underlying reasons for the effectiveness of direct methods in determining atomic structures.

Main Methods:

Analysis of phase distribution properties in electron diffraction.
Exploitation of prior work on anomalous scattering effects in direct methods.
Numerical calculations to support theoretical findings.

Related Experiment Videos

Main Results:

The summation operator(0) distribution of reflection phases remains effectively kinematical, with a narrow distribution, even for thicker samples.
This narrow phase distribution validates the use of direct methods and structural refinements.
Large unit-cell structures with random atomic positions exhibit an effective statistical kinematical approximation.

Conclusions:

The success of direct methods in electron diffraction is not a mirage but is rooted in the effectively kinematical nature of phase distributions.
Positivity constraints and heavy atom dominance are not strictly required for these methods to be valid.
The findings reconcile theoretical limitations with experimental successes in atomic structure determination.