Melting of Aromatic Compounds: Molecular Dynamics Simulations

1995 ◽  
Vol 408 ◽  
Author(s):  
P. W.-C. Kung ◽  
J. T. Books ◽  
C. M. Freeman ◽  
S. M. Levine ◽  
B. Vessali ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Crystal ◽  
Constant Pressure ◽  
Molecular Crystals ◽  
Melting Transition ◽  
Melting Temperatures ◽  
Molecular Dynamics Calculations ◽  
Dynamics Simulations ◽  
Experimental Melting Point ◽  
Experimental Melting

AbstractWe have used constant pressure molecular dynamics calculations to explore the behavior at various temperatures of two molecular crystals: benzene and a brominated phenyl compound. We observed a melting transition by heating the crystals from a low temperature. In the case of benzene, we performed one heating run of about 1 ns and obtained agreement with the experimental melting point to within some 8%. We have also simulated the melting of a more complex molecular crystal that contains bromine and phenyl groups. We performed four heating runs, with different rates of heating. For total simulation times of about 100, 220, 770, and 1 I50ps, the heating runs predicted melting temperatures that differed from the experimental melting temperature by 53%, 33%, 25%, and 9% respectively.

Molecular Dynamics Simulations on Melting of Aluminum

2013 ◽  
Vol 423-426 ◽  
pp. 935-938 ◽  
Author(s):  
Ji Feng Li ◽  
Xiao Ping Zhao ◽  
Jian Liu
Keyword(s):  
Molecular Dynamics ◽  
Melting Point ◽  
Molecular Dynamics Simulations ◽  
High Pressures ◽  
Ambient Pressure ◽  
Initial Porosity ◽  
Equilibrium Melting Point ◽  
Porosity Effect ◽  
Dynamics Simulations ◽  
Experimental Melting Point

Molecular dynamics simulations were performed to calculate the melting points of perfect crystalline aluminum to high pressures. Under ambientpressure, there exhibits about 20% superheating before melting compared to the experimental melting point. Under high pressures, thecalculated melting temperature increases with the pressure but at a decreasing rate, which agrees well with the Simon's melting equation. Porosity effect was also studied for aluminum crystals with various initial porosity at ambient pressure, which shows that the equilibrium melting point decreases with the initial porosity as experiments expect.

scholarly journals Car–Parrinello and path integral molecular dynamics study of the intramolecular hydrogen bonds in the crystals of benzoylacetone and dideuterobenzoylacetone

2014 ◽  
Vol 16 (42) ◽  
pp. 23026-23037 ◽  
Author(s):  
Piotr Durlak ◽  
Zdzisław Latajka
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Ab Initio ◽  
Path Integral ◽  
Molecular Crystal ◽  
Short Hydrogen Bond ◽  
Deuterated Analogue ◽  
Dynamics Simulations ◽  
Intramolecular Hydrogen

The dynamics of the intramolecular short hydrogen bond in the molecular crystal of benzoylacetone and its deuterated analogue are investigated using ab initio molecular dynamics simulations.

Melting at Mg/Al interface in Mg-Al-Mg nanolayer by molecular dynamics simulations

2021 ◽  
Author(s):  
Xue-Qi Lv ◽  
Xiong-Ying Li
Keyword(s):  
Molecular Dynamics ◽  
Heat Capacity ◽  
Distribution Function ◽  
Potential Energy ◽  
Density Distribution ◽  
Molecular Dynamics Simulations ◽  
Regional Research ◽  
Melting Temperatures ◽  
Essential Step ◽  
Dynamics Simulations

Abstract The melting at the magnesium/aluminum (Mg/Al) interface is an essential step during the fabrications of Mg-Al structural materials and biomaterials. We carried out molecular dynamics simulations on the melting at the Mg/Al interface in a Mg-Al-Mg nanolayer via analyzing the changes of average atomic potential energy, Lindemann index, heat capacity, atomic density distribution and radial distribution function with temperature. The melting temperatures (T m) of the nanolayer and the slabs near the interface are significantly sensitive to the heating rate (v h) over the range of v h≤4.0 K/ps. The distance (d) range in which the interface affects the melting of the slabs is predicted to be (-98.2, 89.9) Å at v h→0, if the interface is put at d=0 and Mg (Al) is located at the left (right) side of the interface. The (T m) of the Mg (Al) slab just near the interface (e.g., d=4.0 Å) is predicted to be 926.8 K (926.6 K) at v h→0, with 36.9 K (37.1 K) below 963.7 K for the nanolayer. These results highlight the importance of regional research on the melting at an interface in the nanolayers consisting of two different metals.

Molecular dynamics simulations of ferroelectricity in di-isopropyl-ammonium halide molecular crystals

2019 ◽  
Vol 730 ◽  
pp. 367-371
Author(s):  
Yundi Huang ◽  
Pengfei Hu ◽  
Jianing Song ◽  
Yongle Li ◽  
Alessandro Stroppa
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Molecular Crystals ◽  
Dynamics Simulations

scholarly journals Insights into mechanochemical reactions at the molecular level: simulated indentations of aspirin and meloxicam crystals

2019 ◽  
Vol 10 (10) ◽  
pp. 2924-2929 ◽  
Author(s):  
Michael Ferguson ◽  
M. Silvina Moyano ◽  
Gareth A. Tribello ◽  
Deborah E. Crawford ◽  
Eduardo M. Bringa ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Molecular Level ◽  
Molecular Crystals ◽  
Classical Molecular Dynamics ◽  
Dynamics Simulations ◽  
Mechanochemical Reactions

Working towards a fundamental description of mechanochemical reactions through the use of classical molecular dynamics simulations. Capturing the transfer of molecules between two non-volatile molecular crystals during mechanochemical events.

Computational Design of Thiourea-based Cyclophane Sensors for Small Anions

2012 ◽  
Vol 65 (3) ◽  
pp. 303 ◽  
Author(s):  
Huifang Xie ◽  
Ming Wah Wong
Keyword(s):  
Molecular Dynamics ◽  
Binding Affinity ◽  
Density Functional ◽  
Computational Design ◽  
Binding Pocket ◽  
Solvent Medium ◽  
Guest Binding ◽  
Molecular Dynamics Calculations ◽  
Anion Complexes ◽  
Dynamics Simulations

The host–guest binding properties of a tri-thiourea cyclophane receptor (1) with several common anions have been investigated using density functional theory (DFT) and molecular dynamics calculations. Receptor 1 is predicted to be an effective receptor for binding small halogen and Y-shaped (NO3– and AcO–) anions in the gas phase, cyclohexane and chloroform. The calculated order of anion binding affinity for the receptor 1 in chloroform is F– > Cl– > AcO– > NO3– >Br– > H2PO4– > HSO4–. The binding free energies are strongly influenced by a dielectric solvent medium. The structures of the receptor–anion complexes are characterized by multiple (typically 6) hydrogen bonds in all cases. The overall binding affinity of various anions is determined by the basicity of anion, size and shape of the binding site, and solvent medium. Explicit chloroform solvent molecular dynamics simulations of selected receptor–anion complexes reveal that the anions are strongly bound within the binding pocket via hydrogen-bonding interactions to all the receptor protons throughout the simulation. A sulfur analogue of receptor 1 (2), with a larger central cavity, is shown to be a more effective sensor than 1 for small anions. Two different approaches to develop the thiourea-based cyclophane receptor into a chromogenic sensor were examined.

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