scholarly journals Structural transformation between long and short-chain form of liquid sulfur from ab initio molecular dynamics

2015 ◽  
Vol 142 (15) ◽  
pp. 154502 ◽  
Author(s):  
Dušan Plašienka ◽  
Peter Cifra ◽  
Roman Martoňák
2014 ◽  
Vol 13 (04) ◽  
pp. 1450024
Author(s):  
Shoutian Sun ◽  
Jianwen Liu ◽  
Zhi-Feng Liu

The cationic complexes of Asparagine (Asn), M +( Asn ), with M + = Li +, Na +, K +, Cs +, and H +, are models for studying the interaction between cations and Asn. Ab initio molecular dynamics (AIMD) method is employed to simulate their behavior at finite temperatures. Structural transformation between conformers is observed, which becomes progressively easier as the cation varies from Li +, to Na +, K +, Cs +, and H +. The fluctuation of the M +– N and M +– O distances and rotation of torsional angles are significant even at room temperature for K +, Cs + and H +. Vibrational profiles based on AIMD trajectories provide insights into the broadening and shifts in relative intensities observed in the vibrational spectra measured by infrared multi-photon dissociation (IRMPD) experiments.


2019 ◽  
Author(s):  
Liqun Cao ◽  
Jinzhe Zeng ◽  
Mingyuan Xu ◽  
Chih-Hao Chin ◽  
Tong Zhu ◽  
...  

Combustion is a kind of important reaction that affects people's daily lives and the development of aerospace. Exploring the reaction mechanism contributes to the understanding of combustion and the more efficient use of fuels. Ab initio quantum mechanical (QM) calculation is precise but limited by its computational time for large-scale systems. In order to carry out reactive molecular dynamics (MD) simulation for combustion accurately and quickly, we develop the MFCC-combustion method in this study, which calculates the interaction between atoms using QM method at the level of MN15/6-31G(d). Each molecule in systems is treated as a fragment, and when the distance between any two atoms in different molecules is greater than 3.5 Å, a new fragment involved two molecules is produced in order to consider the two-body interaction. The deviations of MFCC-combustion from full system calculations are within a few kcal/mol, and the result clearly shows that the calculated energies of the different systems using MFCC-combustion are close to converging after the distance thresholds are larger than 3.5 Å for the two-body QM interactions. The methane combustion was studied with the MFCC-combustion method to explore the combustion mechanism of the methane-oxygen system.


2021 ◽  
Vol 22 (9) ◽  
pp. 4378
Author(s):  
Anna Helena Mazurek ◽  
Łukasz Szeleszczuk ◽  
Dariusz Maciej Pisklak

This review focuses on a combination of ab initio molecular dynamics (aiMD) and NMR parameters calculations using quantum mechanical methods. The advantages of such an approach in comparison to the commonly applied computations for the structures optimized at 0 K are presented. This article was designed as a convenient overview of the applied parameters such as the aiMD type, DFT functional, time step, or total simulation time, as well as examples of previously studied systems. From the analysis of the published works describing the applications of such combinations, it was concluded that including fast, small-amplitude motions through aiMD has a noticeable effect on the accuracy of NMR parameters calculations.


ACS Omega ◽  
2021 ◽  
Author(s):  
Khagendra Baral ◽  
Saro San ◽  
Ridwan Sakidja ◽  
Adrien Couet ◽  
Kumar Sridharan ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document