Direct Dynamics Simulations of the 3CH2 + 3O2 Reaction at High Temperature

2021 ◽  
Author(s):  
Sandhiya Lakshmanan ◽  
Subha Pratihar ◽  
William L. Hase
Keyword(s):  
High Temperature ◽  
Direct Dynamics ◽  
Dynamics Simulations

Modeling the Effects of O-sulfonation on the CID of Serine

2020 ◽  
Author(s):  
Kenneth Lucas ◽  
George Barnes
Keyword(s):  
Sulfo Group ◽  
High Energy ◽  
Empirical Method ◽  
Side Chain ◽  
Energy Structure ◽  
Direct Dynamics ◽  
Theoretical Mass ◽  
Intermolecular Proton Transfer ◽  
Dynamics Simulations ◽  
Semi Empirical

We present the results of direct dynamics simulations and DFT calculations aimed at elucidating the effect of \textit{O}-sulfonation on the collision induced dissociation for serine. Towards this end, direct dynamics simulations of both serine and sulfoserine were performed at multiple collision energies and theoretical mass spectra obtained. Comparisons to experimental results are favorable for both systems. Peaks related to the sulfo group are identified and the reaction dynamics explored. In particular, three significant peaks (m\z 106, 88, and 81) seen in the theoretical mass spectrum directly related to the sulfo group are analyzed as well as major peaks shared by both systems. Our analysis shows that the m\z 106 peaks result from intramolecular rearrangements, intermolecular proton transfer among complexes composed of initial fragmentation products, and at high energy side-chain fragmentation. The \mz 88 peak was found to contain multiple constitutional isomers, including a previously unconsidered, low energy structure. It was also seen that the RM1 semi empirical method was not able to obtain all of the major peaks seen in experiment for sulfoserine. In contrast, PM6 did obtain all major experimental peaks.

scholarly journals Reactive molecular dynamics simulation of the high-temperature pyrolysis of 2,2′,2′′,4,4′,4′′,6,6′,6′′-nonanitro-1,1′:3′,1′′-terphenyl (NONA)

RSC Advances ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 5507-5515
Author(s):  
Liang Song ◽  
Feng-Qi Zhao ◽  
Si-Yu Xu ◽  
Xue-Hai Ju
Keyword(s):  
Molecular Dynamics ◽  
High Temperature ◽  
Molecular Dynamics Simulation ◽  
Molecular Dynamics Simulations ◽  
Dynamics Simulation ◽  
Reactive Molecular Dynamics ◽  
Ring Compounds ◽  
Fused Ring ◽  
Dynamics Simulations

The bimolecular and fused ring compounds are found in the high-temperature pyrolysis of NONA using ReaxFF molecular dynamics simulations.

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 Measurements and ab initio molecular dynamics simulations of the high temperature ferroelectric transition in hexagonal RMnO3

2011 ◽  
Vol 110 (8) ◽  
pp. 084116 ◽  
Author(s):  
T. A. Tyson ◽  
T. Wu ◽  
H. Y. Chen ◽  
J. Bai ◽  
K. H. Ahn ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
High Temperature ◽  
Ab Initio ◽  
Molecular Dynamics Simulations ◽  
Ab Initio Molecular Dynamics ◽  
Ferroelectric Transition ◽  
Dynamics Simulations

Mechanism of Thiolate-Disulfide Exchange: Addition–Elimination or Effectively SN2? Effect of a Shallow Intermediate in Gas-Phase Direct Dynamics Simulations

2012 ◽  
Vol 116 (47) ◽  
pp. 11492-11499 ◽  
Author(s):  
Manikandan Paranjothy ◽  
Matthew R. Siebert ◽  
William L. Hase ◽  
Steven M. Bachrach
Keyword(s):  
Gas Phase ◽  
Disulfide Exchange ◽  
Direct Dynamics ◽  
Dynamics Simulations
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