scholarly journals Imaging of alignment and structural changes of carbon disulfide molecules using ultrafast electron diffraction

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Jie Yang ◽  
Joshua Beck ◽  
Cornelis J. Uiterwaal ◽  
Martin Centurion
Science ◽  
2020 ◽  
Vol 368 (6493) ◽  
pp. 885-889 ◽  
Author(s):  
Jie Yang ◽  
Xiaolei Zhu ◽  
J. Pedro F. Nunes ◽  
Jimmy K. Yu ◽  
Robert M. Parrish ◽  
...  

Simultaneous observation of nuclear and electronic motion is crucial for a complete understanding of molecular dynamics in excited electronic states. It is challenging for a single experiment to independently follow both electronic and nuclear dynamics at the same time. Here we show that ultrafast electron diffraction can be used to simultaneously record both electronic and nuclear dynamics in isolated pyridine molecules, naturally disentangling the two components. Electronic state changes (S1→S0 internal conversion) were reflected by a strong transient signal in small-angle inelastic scattering, and nuclear structural changes (ring puckering) were monitored by large-angle elastic diffraction. Supported by ab initio nonadiabatic molecular dynamics and diffraction simulations, our experiment provides a clear view of the interplay between electronic and nuclear dynamics of the photoexcited pyridine molecule.


Author(s):  
N. Uyeda ◽  
E. J. Kirkland ◽  
B. M. Siegel

The direct observation of structural change by high resolution electron microscopy will be essential for the better understanding of the damage process and its mechanism. However, this approach still involves some difficulty in quantitative interpretation mostly being due to the quality of obtained images. Electron diffraction, using crystalline specimens, has been the method most frequently applied to obtain a comparison of radiation sensitivity of various materials on the quantitative base. If a series of single crystal patterns are obtained the fading rate of reflections during the damage process give good comparative measures. The electron diffraction patterns also render useful information concerning the structural changes in the crystal. In the present work, the radiation damage of potassium tetracyano-platinate was dealt with on the basis two dimensional observation of fading rates of diffraction spots. KCP is known as an ionic crystal which possesses “one dimensional” electronic properties and it would be of great interest to know if radiation damage proceeds in a strongly asymmetric manner.


2021 ◽  
Vol 15 (2) ◽  
pp. 2170013
Author(s):  
Junho Shin ◽  
Hyun Woo Kim ◽  
In Hyung Baek ◽  
Sunjeong Park ◽  
Hyeon Sang Bark ◽  
...  

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Hyeongsub So ◽  
Ro Woon Lee ◽  
Sung Taek Hong ◽  
Kyou-Hyun Kim

AbstractWe investigate the sensitivity of symmetry quantification algorithms based on the profile R-factor (Rp) and the normalized cross-correlation (NCC) coefficient (γ). A DM (Digital Micrograph©) script embedded in the Gatan digital microscopy software is used to develop the symmetry quantification program. Using the Bloch method, a variety of CBED patterns are simulated and used to investigate the sensitivity of symmetry quantification algorithms. The quantification results show that two symmetry quantification coefficients are significantly sensitive to structural changes even for small strain values of < 1%.


2018 ◽  
Vol 10 (5) ◽  
Author(s):  
Dalong Qi ◽  
Chengshuai Yang ◽  
Fengyan Cao ◽  
Jinyang Liang ◽  
Yilin He ◽  
...  

Author(s):  
Joao Pedro Figueira Nunes ◽  
Kathryn Ledbetter ◽  
Ming-Fu Lin ◽  
Michael Kozina ◽  
Elisa Biasin ◽  
...  

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