Article
Physics, Fluids & Plasmas
Philipp Stroeker, Karsten Meier
Summary: The methodology developed by Lustig is applied to derive rigorous expressions for thermodynamic properties of fluids in the grand canonical ensemble, which are expressed by phase-space functions related to derivatives of the grand canonical potential. The derived expressions are validated by Monte Carlo simulations, providing more reliable results compared to previous literature and becoming equivalent to corresponding expressions in the canonical ensemble in the thermodynamic limit.
Article
Mechanics
Pipat Harata, Prathan Srivilai
Summary: We calculate the grand canonical partition function of a serial metallic island system using the imaginary-time path integral formalism. All electronic excitations in the lead and island electrodes are described using Grassmann numbers, and the Coulomb charging energy is represented in terms of phase fields. By using the large channel approximation, we determine the explicit phase dependence of the tunneling action. The partition function is represented as a path integral over phase fields, with a path probability given in an analytically known effective action functional. Additionally, we propose a method to calculate the average electron number and construct the quantum stability diagram of the serial island system using winding numbers.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2022)
Article
Physics, Multidisciplinary
Tobias Dornheim
Summary: A practical analysis of the fermion sign problem in fermionic path integral Monte Carlo simulations in the grand-canonical ensemble showed that the sign problem in the GCE is more severe than in the canonical ensemble. Despite these challenges, fermionic PIMC simulations in the GCE are still feasible in many cases, providing access to important quantities for research fields such as warm dense matter, ultracold atoms, and electrons in quantum dots.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Chemistry, Physical
Jiayan Xu, Wenbo Xie, Yulan Han, P. Hu
Summary: This work develops a machine learning potential for simulating chemical systems and uses large-scale simulations to track catalyst surface structure changes during oxidations, revealing the stages and mechanisms of Pt surface oxidation.
Article
Chemistry, Physical
Vitaly A. Gorbunov, Anastasiia I. Uliankina, Pavel Stishenko, Alexander Myshlyavtsev
Summary: The self-assembly of TPyB-Cu networks on MXene surface was investigated, revealing different local environments and thermal stabilities of metal-organic structures. The self-assembly offers opportunities for stabilizing and tuning catalyst properties.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Jeongmin Kim, Luc Belloni, Benjamin Rotenberg
Summary: Molecular simulations that involve ion exchange in an open environment are important for studying various systems. A recent development in hybrid nonequilibrium molecular dynamics/Monte Carlo algorithms allows efficient computation of fluctuating number or charge density in dense fluids or ionic solutions. By optimizing electrostatic interactions and using bias-based methods, this approach significantly enhances the efficiency of salt-pair exchange in Lennard-Jones electrolytes.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
Cole Miles, Benjamin Cohen-Stead, Owen Bradley, Steven Johnston, Richard Scalettar, Kipton Barros
Summary: We present a method to simplify Monte Carlo simulations in the grand canonical ensemble by imposing a fictitious dynamics on the chemical potential. The method runs concurrently with the Monte Carlo sampling of the physical system and corrects the chemical potential based on time-averaged estimates of the mean and variance of the particle number. We performed various tests and found rapid convergence of the chemical potential in all cases, with the inexactness of the tuning algorithm contributing only a minor part of the total measurement error for realistic simulations.
Article
Chemistry, Physical
D. Caviedes, I. Cabria
Summary: In this study, the Grand Canonical Monte Carlo simulations were used to investigate the hydrogen storage capacities of different carbon nanopores shapes under various conditions. It was found that the storage capacities of pores increase with the curvature of the pores.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Nanoscience & Nanotechnology
Vrindaa Somjit, Bilge Yildiz
Summary: Identifying the structure of the Al2O3/Al interface is crucial for enhancing its performance in various applications. This study utilizes ab initio grand canonical Monte Carlo to explore the composition and configuration space of the interface, revealing its atomically sharp and layer-by-layer propagation nature. The insights obtained contribute to the design and engineering of Al2O3/Al-based corrosion coatings, controllable transistor technologies, and noise-free superconducting qubits.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Ceramics
Georgy Lazorenko, Anton Kasprzhitskii
Summary: A comparative study on water sorption by different components of the binder phase formed in geopolymerization was conducted using the GCMC simulation method. The results showed that structural changes in the host framework significantly affect water sorption properties. The simulation results provide valuable information on the behavior of water confined in geopolymeric binder phase, contributing to a better understanding of water adsorption mechanism.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Physical
Peng Bai, Matthew Neurock, J. Ilja Siepmann
Summary: This study utilizes first-principles grand-canonical simulations to predict water adsorption on H-ZSM-5 zeolites under specified experimental conditions, with the use of inexpensive force fields and a pool-based parallelization algorithm to improve simulation efficiency. The results show that H+ exchange significantly increases the hydrophilicity of zeolite MFI and a substantial amount of water is present even at very low relative humidities.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Biochemistry & Molecular Biology
Yunhui Ge, Oliver J. Melling, Weiming Dong, Jonathan W. Essex, David L. Mobley
Summary: Water plays a crucial role in protein-ligand interactions, but its slow rearrangement during binding can often hinder accurate free energy calculations. Previous studies have shown that grand canonical Monte Carlo (GCMC) simulations outperform normal molecular dynamics (MD) simulations in water sampling, but there is still room for improvement. In this work, we applied GCMC to evaluate its performance in rehydrating buried water sites in 21 protein-ligand systems. We found that while GCMC was successful in most systems, it failed in five systems due to protein/ligand motions obstructing water insertion. To overcome this, we extended our simulations and introduced a new technique called grand canonical nonequilibrium candidate Monte Carlo (GCNCMC), which showed promising results in rehydrating all target water sites in three out of the five problematic systems.
JOURNAL OF COMPUTER-AIDED MOLECULAR DESIGN
(2022)
Article
Chemistry, Applied
Christopher Kessler, Johannes Eller, Joachim Gross, Niels Hansen
Summary: A classical density functional theory (cDFT) based on the PC-SAFT equation of state is proposed for the calculation of adsorption equilibria in covalent organic frameworks (COFs). The results show excellent agreement between PC-SAFT DFT and GCMC simulations for adsorption isotherms in COFs, indicating the predictive power of the method in selective accumulation of longer hydrocarbons in binary mixtures.
MICROPOROUS AND MESOPOROUS MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
S. Sina Moeini-Ardakani, S. Mohadeseh Taheri-Mousavi, Ju Li
Summary: Interstitial alloying elements in metals play a crucial role in influencing their properties, but limitations in experimental and numerical tools hinder efforts to model these mechanisms effectively. Our efficient framework for hybrid simulations demonstrates significant improvements in computational cost and scalability compared to existing libraries.
MODELLING AND SIMULATION IN MATERIALS SCIENCE AND ENGINEERING
(2021)
Article
Chemistry, Multidisciplinary
Ruyi Zhao, Guodong Liu, Guohua Wei, Jihui Gao, Huilin Lu
Summary: By embedding different functional groups at the edge of nanoporous carbons, this study found that acidic oxygenous groups or basic nitrogenous groups can enhance the physisorption capacity of SO2, and increase the polarity of the adsorbent, thereby enhancing the SO2 adsorption capacity.
Article
Engineering, Chemical
Chaiyot Tangsathitkulchai, Suravit Naksusuk, Atichat Wongkoblap, Poomiwat Phadungbut, Prapassorn Borisut
Summary: The study investigated the equilibrium and kinetics of CO2 adsorption by coconut-shell activated carbon impregnated with sodium hydroxide at 273 K. The CO2 adsorption increased with NaOH loading and exhibited three distinctive regions. The results showed an empirical correlation between effective pore diffusivity, CO2 adsorption, and NaOH loading.
Article
Biochemistry & Molecular Biology
Pakamas Kohmuean, Worapoj Inthomya, Atichat Wongkoblap, Chaiyot Tangsathitkulchai
Summary: Experimental and simulation studies of adsorption of carbon dioxide and methane in porous activated carbon and carbon nanotube show sensitivity to pore width, with observed isotherm crossings due to molecular packing. Derived pore size distribution from methane or carbon dioxide adsorption data on activated carbon agreed well with analysis of nitrogen adsorption data, and allowed for accurate description of isotherms at various temperatures and for mixtures of carbon dioxide and methane. Good agreement between computed and experimental isotherm data supports the use of a simple adsorption model.