Homogeneous nucleation in vapor-liquid phase transition of Lennard-Jones fluids: A density functional theory approach

2011 ◽  
Vol 134 (2) ◽  
pp. 024502 ◽  
Author(s):  
Satinath Ghosh ◽  
Swapan K. Ghosh
Keyword(s):  
Phase Transition ◽  
Density Functional Theory ◽  
Liquid Phase ◽  
Homogeneous Nucleation ◽  
Density Functional ◽  
Theory Approach ◽  
Functional Theory ◽  
Liquid Phase Transition ◽  
Lennard Jones ◽  
Vapor Liquid

scholarly journals Vapor−Liquid Interface of the Lennard-Jones Truncated and Shifted Fluid: Comparison of Molecular Simulation, Density Gradient Theory, and Density Functional Theory

2021 ◽  
Author(s):  
Simon Stephan ◽  
Jinlu Liu ◽  
Kai Langenbach ◽  
Walter G. Chapman ◽  
Hans Hasse
Keyword(s):  
Density Functional Theory ◽  
Density Gradient ◽  
Density Functional ◽  
Computer Experiments ◽  
Liquid Interface ◽  
Gradient Theory ◽  
Functional Theory ◽  
Lennard Jones ◽  
Density Gradient Theory ◽  
Vapor Liquid

The vapor-liquid interface of the Lennard-Jones truncated and shifted (LTJS) fluid with a cut-off radius of 2.5 σ is investigated for temperatures covering the range between the triple point and the critical point. Three different approaches to model the vapor-liquid interface are used: molecular dynamics (MD) simulations, density gradient theory (DGT) and density functional theory (DFT). The surface tension, pressure and density profiles, including the oscillatory layering structure of the fluid at the interface, are investigated. The PeTS (Perturbed truncated and shifted) equation of state and PeTS-i functional, based on perturbation theory, are used to calculate the Helmholtz free energy in the DGT and DFT approach. They are consistent with the LJTS force field model. Overall, both DGT and DFT describe the results from computer experiments well. An oscillatory layering structure is found in MD and DFT.

scholarly journals Simulating diffusion in the conditions of vapor-liquid phase transition by the molecular dynamics method

2021 ◽  
Vol 2057 (1) ◽  
pp. 012114
Author(s):  
G V Kharlamov
Keyword(s):  
Phase Transition ◽  
Molecular Dynamics ◽  
Diffusion Coefficient ◽  
Liquid Phase ◽  
Diffusion Coefficients ◽  
Universal Function ◽  
Liquid Phase Transition ◽  
Lennard Jones ◽  
Almost All ◽  
Vapor Liquid

Abstract The molecular dynamics calculations of diffusion coefficients in binary Lennard-Jones systems have been carried out. The parameters of Lennard-Jones potentials correspond to argon and krypton atoms. The universal dependence of the reduced diffusion coefficient of krypton atoms on density for the homogeneous systems of low and middle densities is found. The deviations of the diffusion coefficients from the universal function are observed for the systems in the vapor – liquid phase transition region. The simulations have shown that almost all krypton atoms have situated inside the liquid phase of argon. Special numerical experiments have shown that the nanodroplets of argon are formed as a result of homogeneous nucleation and then the krypton atoms are captured by these droplets. This phenomenon decreases the diffusion coefficient of krypton atoms greatly.

scholarly journals Tuning the optoelectronic properties of hematite with rhodium doping for photoelectrochemical water splitting using density functional theory approach

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdur Rauf ◽  
Muhammad Adil ◽  
Shabeer Ahmad Mian ◽  
Gul Rahman ◽  
Ejaz Ahmed ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Optical Absorption ◽  
Water Splitting ◽  
Density Functional ◽  
Formation Energy ◽  
Visible Region ◽  
Photoelectrochemical Water Splitting ◽  
Theory Approach ◽  
Functional Theory

AbstractHematite (Fe2O3) is one of the best candidates for photoelectrochemical water splitting due to its abundance and suitable bandgap. However, its efficiency is mostly impeded due to the intrinsically low conductivity and poor light absorption. In this study, we targeted this intrinsic behavior to investigate the thermodynamic stability, photoconductivity and optical properties of rhodium doped hematite using density functional theory. The calculated formation energy of pristine and rhodium doped hematite was − 4.47 eV and − 5.34 eV respectively, suggesting that the doped material is thermodynamically more stable. The DFT results established that the bandgap of doped hematite narrowed down to the lower edge (1.61 eV) in the visible region which enhanced the optical absorption and photoconductivity of the material. Moreover, doped hematite has the ability to absorb a broad spectrum (250–800) nm. The enhanced optical absorption boosted the photocurrent and incident photon to current efficiency. The calculated results also showed that the incorporation of rhodium in hematite induced a redshift in optical properties.

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