Search results for "reverse Monte Carlo"
showing 10 items of 32 documents
Advanced approach to the local structure reconstruction and theory validation on the example of the W L 3 -edge extended x-ray absorption fine struct…
2018
The authors gratefully acknowledge the assistance of the ELETTRA XAFS beamline staff members during the EXAFS experiment No 20150303. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014-2018 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission.
Atomistic theory of mesoscopic pattern formation induced by bimolecular surface reactions between oppositely charged molecules
2011
The kinetics of mesoscopic pattern formation is studied for a reversible A+B⇌0 reaction between mobile oppositely charged molecules at the interface. Using formalism of the joint correlation functions, non-equilibrium charge screening and reverse Monte Carlo methods, it is shown that labyrinth-like percolation structure induced by (even moderate-rate) reaction is principally non-steady-state one and is associated with permanently growing segregation of dissimilar reactants and aggregation of similar reactants into mesoscopic size domains. A role of short-range and long-range reactant interactions in pattern formation is discussed.
Local structure and dynamics of wurtzite‐type ZnO from simulation‐based EXAFS analysis
2014
Conventional methods of EXAFS data analysis are often limited to the nearest coordination shells of the absorbing atom due to the difficulties in accurate accounting for the so-called multiple-scattering effects. Besides, it is often difficult to resolve the non-equivalent groups of atoms in a single coordination shell due to strong correlation between structural parameters. In this study we overcome these problems by applying two different simulation-based methods, i.e., classical molecular dynamics (MD) and reverse Monte with evolutionary algorithm (EA), to the analysis of the Zn K-edge EXAFS data for wurtzite-type bulk ZnO. The RMC/EA-EXAFS method allowed us to separate the contributions…
Statistical characterization of self-assembled charged nanoparticle structures
2013
We propose a novel approach for description of dynamics of nanostructure formation for a system consisting of oppositely charged particles. The combination of numerical solution of analytical Bogolyubov–Born–Green–Kirkwood–Yvon (BBGKY) type equation set with reverse Monte Carlo (RMC) method allows us to overcome difficulties of standard approaches, such as kinetic Monte Carlo or Molecular Dynamics, to describe effects of long-range Coulomb interactions. Moreover, this allows one to study the system dynamics on realistic time and length scales. We applied this method to a simple short-range Lenard–Jones (LJ)-like three- (3D) and two-dimensional (2D) system combining the long-range Coulomb an…
Recent progress in high pressure X-ray absorption spectroscopy studies at the ODE beamline
2020
I.J. and A.K. are grateful to the Latvian Council of Science project no. lzp-2018/2-0353 for financial support. The research leading to these results has been partially supported by the project CALIPSOplus under the Grant Agreement No. 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020.
Low temperature X-ray absorption spectroscopy study of $CuMoO_{4}$ and $CuMo_{0.90}W_{0.10}O_4$ using reverse Monte-Carlo method
2020
Radiation physics and chemistry 175, 108411 (2020). doi:10.1016/j.radphyschem.2019.108411
Some necessary background
2005
Theory of non-equilibrium critical phenomena in three-dimensional condensed systems of charged mobile nanoparticles.
2014
A study of 3d electrostatic self-assembly (SA) in systems of charged nanoparticles (NPs) is one of the most difficult theoretical problems. In particular, the limiting case of negligible or very low polar media (e.g. salt) concentration, where the long-range NP interactions cannot be reduced to commonly used effective short-range (Yukawa) potentials, remains unstudied. Moreover, the present study has demonstrated that unlike the Debye–Huckel theory, a complete screening of the charges in SA kinetics (dynamic SA) is not always possible. Generally speaking, one has to take into account implicitly how each NP interacts with all other NPs (the true long-range interactions). Traditional theoreti…
Microscopic approach to the kinetics of pattern formation of charged molecules on surfaces.
2010
A microscopic formalism based on computing many-particle densities is applied to the analysis of the diffusion-controlled kinetics of pattern formation in oppositely charged molecules on surfaces or adsorbed at interfaces with competing long-range Coulomb and short-range Lennard-Jones interactions. Particular attention is paid to the proper molecular treatment of energetic interactions driving pattern formation in inhomogeneous systems. The reverse Monte Carlo method is used to visualize the spatial molecular distribution based on the calculated radial distribution functions (joint correlation functions). We show the formation of charge domains for certain combinations of temperature and dy…
Pressure-induced structural changes in α-MoO3 probed by X-ray absorption spectroscopy
2019
The authors are grateful to Prof. Alain Polian for providing NDAC cell. The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. The work was supported by philanthropist MikroTik and administrated by the University of Latvia Foundation.