Ab Initio Molecular Dynamics of High-Temperature Unimolecular Dissociation of Gas-Phase RDX and Its Dissociation Products

2015 ◽  
Vol 119 (12) ◽  
pp. 2747-2759 ◽  
Author(s):  
Igor V. Schweigert
Keyword(s):  
Molecular Dynamics ◽  
High Temperature ◽  
Ab Initio ◽  
Gas Phase ◽  
Ab Initio Molecular Dynamics ◽  
Unimolecular Dissociation

scholarly journals Study of High-Temperature Behaviour of ZnO by Ab Initio Molecular Dynamics Simulations and X-ray Absorption Spectroscopy

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5206
Author(s):  
Dmitry Bocharov ◽  
Inga Pudza ◽  
Konstantin Klementiev ◽  
Matthias Krack ◽  
Alexei Kuzmin
Keyword(s):  
Molecular Dynamics ◽  
High Temperature ◽  
Ab Initio ◽  
Ab Initio Molecular Dynamics ◽  
Mean Square ◽  
Structural Anisotropy ◽  
X Ray ◽  
Temperature Dependences ◽  
Dynamics Simulations ◽  
X Ray Absorption

Wurtzite-type zinc oxide (w-ZnO) is a widely used material with a pronounced structural anisotropy along the c axis, which affects its lattice dynamics and represents a difficulty for its accurate description using classical models of interatomic interactions. In this study, ab initio molecular dynamics (AIMD) was employed to simulate a bulk w-ZnO phase in the NpT ensemble in the high-temperature range from 300 K to 1200 K. The results of the simulations were validated by comparison with the experimental Zn K-edge extended X-ray absorption fine structure (EXAFS) spectra and known diffraction data. AIMD NpT simulations reproduced well the thermal expansion of the lattice, and the pronounced anharmonicity of Zn–O bonding was observed above 600 K. The values of mean-square relative displacements and mean-square displacements for Zn–O and Zn–Zn atom pairs were obtained as a function of interatomic distance and temperature. They were used to calculate the characteristic Einstein temperatures. The temperature dependences of the O–Zn–O and Zn–O–Zn bond angle distributions were also determined.

scholarly journals Ab initio molecular dynamics study of the interaction of plutonium with oxygen in the gas phase

RSC Advances ◽  
2017 ◽  
Vol 7 (57) ◽  
pp. 36038-36047
Author(s):  
QingQing Wang ◽  
WenLang Luo ◽  
XiaoLi Wang ◽  
Tao Gao
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Gas Phase ◽  
Ab Initio Molecular Dynamics ◽  
Surface Corrosion

There are two kinds of plutonium surface corrosion, one of which is oxidation between plutonium and oxygen or oxygen compounds.

scholarly journals Full Assignment of Ab-Initio Raman Spectra at Finite Temperatures Using Wannier Polarizabilities: Application to Cyclohexane Molecule in Gas Phase

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1212
Author(s):  
Pouya Partovi-Azar ◽  
Thomas Kühne
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Gas Phase ◽  
Raman Spectra ◽  
Predictive Power ◽  
Ab Initio Molecular Dynamics ◽  
Spatial Spread ◽  
Wannier Functions ◽  
Different Types ◽  
Cross Correlations

We demonstrate how to fully ascribe Raman peaks simulated using ab initio molecular dynamics to specific vibrations in the structure at finite temperatures by means of Wannier functions. Here, we adopt our newly introduced method for the simulation of the Raman spectra in which the total polarizability of the system is expressed as a sum over Wannier polarizabilities. The assignment is then based on the calculation of partial Raman activities arising from self- and/or cross-correlations between different types of Wannier functions in the system. Different types of Wannier functions can be distinguished based on their spatial spread. To demonstrate the predictive power of this approach, we applied it to the case of a cyclohexane molecule in the gas phase and were able to fully assign the simulated Raman peaks.

Effect of anion reorientation on proton mobility in the solid acids family CsHyXO4 (X = S, P, Se, y = 1, 2) from ab initio molecular dynamics simulations

2020 ◽  
Vol 22 (19) ◽  
pp. 10738-10752 ◽  
Author(s):  
Christian Dreßler ◽  
Daniel Sebastiani
Keyword(s):  
Molecular Dynamics ◽  
High Temperature ◽  
Proton Transfer ◽  
Ab Initio ◽  
Solid Acids ◽  
Ab Initio Molecular Dynamics ◽  
Proton Mobility ◽  
Transfer Rates ◽  
High Proton ◽  
Dynamics Simulations

The high temperature phases of the solid acids CsHSeO4, CsHSO4 and CsH2PO4 show extraordinary high proton conductivities, which are enabled by the interplay of high proton transfer rates and frequent anion reorientation.

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