Probing Detonation Physics and Chemistry Using Molecular Dynamics and Quantum Chemistry Techniques

1995 ◽  
Vol 418 ◽  
Author(s):  
M. D. Cook ◽  
J. Fellows ◽  
P. J. Haskins

AbstractModem quantum chemistry and molecular dynamics computer codes are powerful tools with which to study the physics and chemistry of energetic materials at the molecular level. Quantum chemistry calculations, on one or two energetic molecules, can give valuable information about the initial steps in their decomposition. Molecular dynamics calculations, even with empirical potentials, can yield important information about the physical processes involved in the initiation and growth of reaction of energetic materials. The combination of Molecular dynamics and quantum chemistry techniques offers the potential to probe energetic material reaction chemistry in real systems, in some detail, in the near future. Such an approach is vital if we are to be able to create new realistic macroscopic models within hydrocodes that can describe the initiation and growth of reaction in explosives. This paper gives an overview of the approach being adopted at DRA Fort Halstead to understanding energetic materials at the molecular level. In particular, the use of quantum chemistry and Molecular dynamics to help construct new macroscopic models will be discussed.

2006 ◽  
Vol 978 ◽  
Author(s):  
Sheng D. Chao

AbstractCurrent large scale atomistic simulations remain too computationally demanding to be generally applicable to industrial and bioengineering materials. It is desirable to develop multiscale modeling algorithms to perform efficient and informative mesoscopic simulations. Here we present a multipolar expansion method to construct coarse grained force fields (CGFF) for polymer nanostructures and nanocomposites. This model can effectively capture the stereochemical response to anisotropic long-range interactions and can be systematically improved upon adding higher order terms. The coarse-graining procedure forms the basis to perform a hierarchy of multiscale simulations starting with the quantum chemistry calculations to coarse grained molecular dynamics, hopefully toward continuum modeling. We have applied this procedure to molecular clusters such as alkane, benzene, and fullerene. For liquid alkane, molecular dynamics simulations using the CGFF can reproduce the pair distribution functions using atomistic force fields. Molecular mechanics simulations using the CGFF can well reproduce the energetics of benzene clusters from quantum chemistry electronic structure calculations. Subtle anisotropy in the interaction potentials of the fullerene dimer using the Brenner force field can also be well represented by the model. It is promising this procedure can be standardized and further extended.


2020 ◽  
Vol 22 (4) ◽  
pp. 1378-1387 ◽  
Author(s):  
Hairui Ji ◽  
Pingli Lv

Mechanistic insights into lignin dissolution behaviors of a recyclable acid hydrotrope (p-TsOH), deep eutectic solvent (DES, ChCl-Lac), and ionic liquid (IL, [Amim][Cl]) were carried out by combined quantum chemistry calculations and molecular dynamics simulations.


Author(s):  
VV Chagovets ◽  
NL Starodubtseva ◽  
VE Frankevich

Investigation of the triazole-derived drugs action mechanisms and understanding of their affinity and specificity molecular basis may contribute to the new drugs development. The study was aimed to investigate the triazoles class representative (fluconazole) complexes with amino acids using mass spectrometry, molecular dynamics and ab initio quantum chemistry calculations. During the experimental study, the fluconazole, alanine, lysine and threonine solutions were analyzed by electrospray ionization mass spectrometry and tandem mass spectrometry. The molecular dynamics modeling of the fluconazole–amino acid complexes was performed using the CHARMM force field. The quantum chemistry calculations of the complexes structure and energy parameters were carried out using the density-functional theory by B3LYP calculations (3-21G and 6-311++G** basis sets). Mass spectra indicated that fluconazole formed stable complexes with amino acids in the 1 : 1 stoichiometric ratio. In accordance with the tandem mass spectrometry with varying fluconazole–amino acid associates ion fragmentation energy, the following sequence was obtained: [Fluc + Ala + H]+ < [Fluc + Lys + H]+ < [Fluc + Thr + H]+. The fluconazole–amino acid interaction energy values resulting from the quantum chemistry calculations formed the sequence similar to that obtained by experiment. Thus, as seen in the case of fluconazole–amino acid complexes, it is possible to combine the experimental mass spectrometry studies with quantum chemical modeling for the complexes properties assessment.


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