Molecular dynamics at constant temperature and pressure

1993 ◽  
Vol 47 (1) ◽  
pp. 343-350 ◽  
Author(s):  
S. Toxvaerd
2013 ◽  
Vol 139 (16) ◽  
pp. 164106 ◽  
Author(s):  
Ross A. Lippert ◽  
Cristian Predescu ◽  
Douglas J. Ierardi ◽  
Kenneth M. Mackenzie ◽  
Michael P. Eastwood ◽  
...  

2020 ◽  
Vol 22 (36) ◽  
pp. 20829-20836
Author(s):  
Cheng Chen ◽  
Xi Jiang

The morphology of nascent soot and the effect of oxygenated additives on sooting mitigation at a constant temperature of 3000 K.


2016 ◽  
Vol 30 (01) ◽  
pp. 1550253 ◽  
Author(s):  
Xinjian Liu ◽  
Yu Jin ◽  
Congliang Huang ◽  
Jingfeng He ◽  
Zhonghao Rao ◽  
...  

Temperature and pressure have direct and remarkable implications for drying and dewatering effect of low rank coals such as lignite. To understand the microenergy change mechanism of lignite, the molecular dynamics simulation method was performed to study the self-diffusion of lignite/water under different temperatures and pressure. The results showed that high temperature and high pressure can promote the diffusion of lignite/water system, which facilitates the drying and dewatering of lignite. The volume and density of lignite/water system will increase and decrease with temperature increasing, respectively. Though the pressure within simulation range can make lignite density increase, the increasing pressure showed a weak impact on variation of density.


2021 ◽  
Vol 55 (6) ◽  
Author(s):  
M. Gokhan Günay ◽  
Ubade Kemerli

A novel nano-scale pump that can transport atoms or small molecules with a peristaltic motion is designed. It is proven by molecular-dynamics simulations that the introduced nano-pump design works properly. The designed nano-pump consists of one main carbon nanotube named the flow tube and two rotors where multi-walled carbon nanotubes are attached. The pumping of helium atoms by the designed peristaltic carbon nano-pump is investigated by molecular-dynamics simulations. For varying rotor speeds and blade counts, time-averaged velocity, temperature, and pressure results of pumped helium atoms are calculated, and relationships between them are modeled as polynomial surfaces. The results showed that rotor frequency increases the velocity of helium linearly and the temperature and pressure of helium non-linearly. Furthermore, the blade count of the proposed mechanism does not substantially affect the velocity as per the previous studies in the literature.


2020 ◽  
Author(s):  
Nicholas Francia ◽  
Louise S. Price ◽  
Jonas Nyman ◽  
Sarah (Sally) Price ◽  
Matteo Salvalaglio

<p>Crystal structure prediction methods are prone to overestimate the number of potential polymorphs of organic molecules. In this work, we aim to reduce the overprediction by systematically applying molecular dynamics simulations and biased sampling methods to cluster subsets of structures that can easily interconvert at finite temperature and pressure. Following this approach, we rationally reduce the number of predicted putative polymorphs in CSP-generated crystal energy landscapes. This uses an unsupervised clustering approach to analyze independent finite-temperature molecular dynamics trajectories and hence identify a representative structure of each cluster of distinct lattice energy minima that are effectively equivalent at finite temperature and pressure. Biased simulations are used to reduce the impact of limited sampling time and to estimate the work associated with polymorphic transformations. We demonstrate the proposed systematic approach by studying the polymorphs of urea and succinic acid, reducing an initial set of over 100 energetically plausible CSP structures to 12 and 27 respectively, including the experimentally known polymorphs. The simulations also indicate the types of disorder and stacking errors that may occur in real structures.<br></p>


1993 ◽  
Vol 47 (5) ◽  
pp. 3145-3151 ◽  
Author(s):  
K. Cho ◽  
J. D. Joannopoulos ◽  
Leonard Kleinman

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