scholarly journals Validation of density functionals for transition metals and intermetallics using data from quantitative electron diffraction

2013 ◽  
Vol 138 (8) ◽  
pp. 084504 ◽  
Author(s):  
Xiahan Sang ◽  
Andreas Kulovits ◽  
Guofeng Wang ◽  
Jörg Wiezorek
Keyword(s):  
Electron Diffraction ◽  
Transition Metals ◽  
Density Functionals ◽  
Using Data

Oxidation von Nickelschichten untersucht mittels Elektronenbeugung / Oxydation of Thin Ni-foils Investigated by Electron Diffraction

1975 ◽  
Vol 30 (4) ◽  
pp. 471-470b
Author(s):  
Siegfried Drautz ◽  
Siegfried Steeb
Keyword(s):  
Electron Diffraction ◽  
Transition Metals ◽  
Group Viii ◽  
Intermediate Phases

Abstract Recrystallized nickel foils were treated by oxygen (2·10-4 Torr up to 10-3 Torr) at temperatures up to 550 °C within an electron diffraction set. The treatment was done isothermal and isobaric during few minutes up to several hours. The change in structure was observed. Additional reflexions occured and could be interpreted as due to double reflexion. Under the conditions mentioned above nickel changed into nickel monoxide directly, i. e. without formation of sub-oxides or other intermediate phases. This is in accordance with the fact that up to now no sub-oxides to the transition metals of group VIII a have been found.

Establishing the Accuracy of Broadly Used Density Functionals in Describing Bulk Properties of Transition Metals

2013 ◽  
Vol 9 (3) ◽  
pp. 1631-1640 ◽  
Author(s):  
Patanachai Janthon ◽  
Sergey M. Kozlov ◽  
Francesc Viñes ◽  
Jumras Limtrakul ◽  
Francesc Illas
Keyword(s):  
Transition Metals ◽  
Density Functionals ◽  
Bulk Properties

scholarly journals Robustness of surface activity electronic structure-based descriptors of transition metals

2018 ◽  
Vol 20 (31) ◽  
pp. 20548-20554 ◽  
Author(s):  
Lorena Vega ◽  
Biel Martínez ◽  
Francesc Viñes ◽  
Francesc Illas
Keyword(s):  
Electronic Structure ◽  
Transition Metal ◽  
Transition Metals ◽  
Coordination Number ◽  
Surface Activity ◽  
Metal Surfaces ◽  
Surface States ◽  
Density Functionals ◽  
Direct Relation ◽  
Transition Metal Surfaces

The d-band centre comes back from the dead being the most consistent of the main electronic descriptors, due to its excellent transferability between five density functionals. The robustness previously observed for bulk is here evaluated for transition metal surfaces and if large surface states are not involved, a direct relation with the coordination number is disclosed.

scholarly journals Facile dissociation of molecular nitrogen using lanthanide surfaces: towards ambient temperature ammonia synthesis

2020 ◽  
Author(s):  
Jay Chan ◽  
Stephanie Lambie ◽  
Joe Trodahl ◽  
Denis Lefebvre ◽  
Maxime Le Ster ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Transition Metals ◽  
Ambient Temperature ◽  
Ammonia Synthesis ◽  
Computational Study ◽  
Molecular Nitrogen ◽  
Electrical Conductance ◽  
Dissociation Pathway ◽  
Lanthanide Metals

A combined experimental and computational study is reported on a hitherto unrecognised single lanthanide catalyst for the breaking of molecular nitrogen and formation of ammonia at ambient temperature and low pressure.<br>We combine in situ electrical conductance and electron diffraction measurements to track the conversion from the lanthanide metals to the insulating lanthanide nitrides.<br>The efficiency of the conversion is then interpreted using DFT+U calculations, suggesting a molecular nitrogen dissociation pathway separate from that well-established for transition metals.<br>Finally, we show that exposure of the lanthanide surfaces to both molecular nitrogen and hydrogen results in the formation of ammonia.<br><br>

scholarly journals Combining precession electron diffraction data with X-ray powder diffraction data to facilitate structure solution

2008 ◽  
Vol 41 (6) ◽  
pp. 1115-1121 ◽  
Author(s):  
Dan Xie ◽  
Christian Baerlocher ◽  
Lynne B. McCusker
Keyword(s):  
Electron Diffraction ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Electron Diffraction Data ◽  
Powder Diffraction Data ◽  
Powder Charge ◽  
X Ray ◽  
Structure Solution ◽  
Precession Electron Diffraction ◽  
Using Data

Information derived from precession electron diffraction (PED) patterns can be used to advantage in combination with high-resolution X-ray powder diffraction data to solve crystal structures that resist solution from X-ray data alone. PED data have been exploited in two different ways for this purpose: (1) to identify weak reflections and (2) to estimate the phases of the reflections in the projection. The former is used to improve the partitioning of the reflection intensities within an overlap group and the latter to provide some starting phases for structure determination. The information was incorporated into a powder charge-flipping algorithm for structure solution. The approaches were first developed using data for the moderately complex zeolite ZSM-5, and then tested on TNU-9, one of the two most complex zeolites known. In both cases, including PED data from just a few projections facilitated structure solution significantly.

Sign in / Sign up

Export Citation Format

Share Document