Article
Physics, Applied
Shubham Malviya, Joseph C. Tapia, Peng Bai
Summary: This paper describes the calculation of adsorption isotherms from molecular dynamics simulations using the two-phase thermodynamic model and the ideal adsorbed gas model. It proposes three routes to compute adsorption isotherms and compares the results with established Monte Carlo methods. The methods provided in this paper offer an alternative approach for computing adsorption isotherms and enable direct comparison with experiments.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Mechanics
M. Beljin-Cavic, I Loncarevic, Lj Budinski-Petkovic, Z. M. Jaksic, S. B. Vrhovac
Summary: This study uses Monte Carlo simulations to investigate the random sequential adsorption of mixtures of objects with varying shapes on a three-dimensional cubic lattice. The research focuses on the influence of geometrical properties of the shapes on the jamming coverage and temporal evolution of density. The results show that the coverage approaches the jamming limit exponentially and the relaxation time is determined by the number of orientations the objects can take on the lattice. The jamming coverage of a mixture can be greater than or in between the jamming coverages of the single-component shapes, depending on the local geometry.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2022)
Article
Multidisciplinary Sciences
Jan Kessler, Francesco Calcavecchia, Thomas D. Kuehne
Summary: Inspired by the universal approximation theorem and the widespread adoption of artificial neural network techniques, feed-forward neural networks are proposed as a general purpose trial wave function for quantum Monte Carlo simulations of continuous many-body systems. The accuracy of the trial wave functions was demonstrated by studying an exactly solvable model system of two trapped interacting particles and the hydrogen dimer. The whole many-body wave function can be represented by a neural network for simple model systems, while the antisymmetry condition of non-trivial fermionic systems is incorporated by means of a Slater determinant.
ADVANCED THEORY AND SIMULATIONS
(2021)
Article
Chemistry, Physical
Tina N. Mihm, Laura Weiler, James J. Shepherd
Summary: This study reveals, for the first time, the contribution mechanisms of Ferroin compounds Fe(CN)3(4e) and Fe(CN)4(2e) to the spectra through analysis of vibrational dynamics and from the perspective of polarized spectra. It is found that the contributions of Fe(CN)3(4e) and Fe(CN)4(2e) exhibit different characteristics in spectral analysis, providing a more comprehensive theoretical understanding.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Tina N. Mihm, Bingdi Yang, James J. Shepherd
Summary: Calculations using coupled cluster on solids have sparked a debate on using a N-1/3 power law for fitting correlation energy when extrapolating to the thermodynamic limit, as opposed to the more commonly used N-1 power law. While N-1/3 power law seems to fit better for large system sizes, analysis suggests that N-1 power law still applies to large systems, with N-1/3 power law occurring only at low N values.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Management
Jeyms Villanueva-Cantillo, Manuel Munoz-Marquez
Summary: This study introduces a method for calculating critical values in variable selection methods in DEA through extensive simulation research, showing consistent results and the potential use of linear models for estimating critical values. Suggestions for future research were also proposed.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2021)
Article
Computer Science, Interdisciplinary Applications
DanHua ShangGuan
Summary: The Monte Carlo method is a powerful tool in many research fields, but the increasing complexity of physical models and mathematical models requires efficient algorithms to overcome the computational cost.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Mechanics
V Dossetti, G. M. Viswanathan, V. M. Kenkre
Summary: This article presents numerical investigations on the validity of the Boltzmann prescription in statistical mechanics for large systems. The study focuses on whether the extensivity of energy implies the extensivity of the Boltzmann entropy. Based on simulations considering a large number of states, the results suggest that the systems studied are still too small to conclusively settle the issues raised. However, the new approach outlined in this study represents a first step towards addressing the question of non-extensive statistical mechanics from first principles.
JOURNAL OF STATISTICAL MECHANICS-THEORY AND EXPERIMENT
(2022)
Article
Physics, Multidisciplinary
A. O. Sorokin
Summary: This study investigates the critical properties of the stacked -J(1) -J(2) Ising model on a cubic lattice. By using Monte Carlo simulations and renormalization group, the researchers find a first-order phase transition for J(2)/J(1) > 1/2 and observe a continuous variation of critical exponents in different ranges.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2022)
Article
Polymer Science
Joao C. O. Guerra, Antonio Cadilhe
Summary: The presence of defects and dirt in actual substrates affects their properties, breaking symmetries and reducing spatial dimensionality. The study shows novel behavior of polymer mass transport on a crystalline substrate when a single attractive impurity is present. The diffusion coefficient is found to have size scaling dependence with the number of monomers in the polymer.
Article
Polymer Science
Hana Ferkous, Karima Rouibah, Nour-El-Houda Hammoudi, Manawwer Alam, Chahrazed Djilani, Amel Delimi, Omar Laraba, Krishna Kumar Yadav, Hyun-Jo Ahn, Byong-Hun Jeon, Yacine Benguerba
Summary: This study investigated the adsorption mechanisms of methylene blue onto olive waste treated with KOH and onto a composite of KOH-treated waste and PEG-silica gel. The research found that electrostatic attraction and hydrogen bond formation are critical for the adsorption process.
Article
Chemistry, Multidisciplinary
Pengfei Tian, Adrien Lemaire, Fabien Senechal, Olivier Habrylo, Viviane Antonietti, Pascal Sonnet, Valerie Lefebvre, Frederikke Isa Marin, Robert B. Best, Jerome Pelloux, Davide Mercadante
Summary: Efficiently designing functional proteins with higher thermal stability is still challenging, especially for highly diverse sequence variants. However, optimizing sequence design based on evolutionary fitness can help improve protein stability. In this study, we used a generative evolution fitness model to design artificial sequences for a proteinaceous inhibitor of pectin methylesterase enzymes. The majority of the designs were functional, and some even showed improved thermal stability. This method has the potential to expand the sequence space of functional proteins with valuable traits for industrial applications and scientific research.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Materials Science, Multidisciplinary
Owen Bradley, George G. Batrouni, Richard T. Scalettar
Summary: The Holstein Hamiltonian describes fermions interacting with phonons on a lattice. It predicts the behavior of dressed quasiparticles and the formation of superconducting and charge density wave phases at different densities. Quantum Monte Carlo calculations have been used to determine critical temperatures for these phase transitions in various lattice geometries.
Article
Materials Science, Multidisciplinary
S. Tarat, Bo Xiao, R. Mondaini, R. T. Scalettar
Summary: This paper investigates the two mechanisms for the vanishing of the sign problem in quantum simulations: whether randomly chosen field configurations have negative det[M(h)], or if the specific subset of configurations chosen by the weighting function have a greater preponderance of negative values. By conducting auxiliary field quantum Monte Carlo simulations of interacting fermions, the relative importance of these two mechanisms can be better understood.
Article
Polymer Science
Jiang Zhang, Wenbing Hu
Summary: The effects of specific chain-end hydrogen-bonding interactions on the once-folding crystallization of 16-mers in PEG were investigated. It was found that these interactions have little influence on the kinetics of nucleation and lateral growth, but create a significant gap at the growth front, leading to the double-lamella phenomenon. The chain-end hydrogen-bonding interactions are abundant at the surfaces of once-folded lamellar crystals, enhancing their metastability and hindering their thickening into chain-extended crystals. Additionally, intra- and inter-molecular secondary nucleation at the folded and extended growth fronts exhibit different growth rate dependencies on the interaction strengths. The study reveals the role of specific chain-end interactions in PEG crystallization.
Article
Chemistry, Physical
Ulrich K. Deiters, Richard J. Sadus
JOURNAL OF PHYSICAL CHEMISTRY B
(2020)
Article
Engineering, Chemical
Ulrich K. Deiters, Ian H. Bell
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2020)
Article
Thermodynamics
Simon Stephan, Ulrich K. Deiters
INTERNATIONAL JOURNAL OF THERMOPHYSICS
(2020)
Article
Thermodynamics
Ulrich K. Deiters, Ian H. Bell
INTERNATIONAL JOURNAL OF THERMOPHYSICS
(2020)
Article
Chemistry, Physical
Eder L. Granados-Bazan, Sergio E. Quinones-Cisneros, Ulrich K. Deiters
Summary: The interfacial properties of binary mixtures composed of fully flexible linear tangent chains were studied, showing that temperature has less influence as the molecular length of the heavy component increases. Long-range interactions contributed around 60% of the surface tension, 20% of the vapor pressure, and 10% of the orthobaric density. Strong enrichment of the volatile component was observed at the interface in asymmetric mixtures.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Biographical-Item
Chemistry, Physical
Nicolaus Dahmen, Ulrich K. Deiters, Dirk Tuma
JOURNAL OF SUPERCRITICAL FLUIDS
(2021)
Article
Engineering, Chemical
Ian H. Bell, Ulrich K. Deiters
Summary: In this work, the superancillary equation approach is extended to classical cubic equations of state to improve the accuracy and speed of calculating thermodynamic phase equilibrium. By using prebuilt Chebyshev expansions for noniterative evaluation, the computational efficiency is significantly improved, making iterative calculations for pure fluid phase equilibria potentially obsolete.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2021)
Article
Chemistry, Physical
Ulrich K. Deiters, Richard J. Sadus
Summary: The study investigates the role of interatomic interactions on the solid-liquid and vapor-liquid equilibria of neon using molecular simulation. It is found that a combination of two-body plus quantum influences has the greatest impact on the accuracy of solid-liquid equilibrium prediction. However, a combination of two-body + three-body + quantum interactions is required to approach experimental accuracy for solid-liquid equilibria as well as predict vapor-liquid equilibria to a high degree of accuracy.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Article
Chemistry, Multidisciplinary
Eder L. Granados-Bazan, Sergio E. Quinones-Cisneros, Ulrich K. Deiters
Summary: Molecular dynamics simulations were used to study cylindrical droplets made up of binary mixtures of Lennard-Jones fluids in contact with a solid substrate. The study focused on the effect of mixing monomeric LJ fluid with heavy components on contact angle and droplet structure, particularly in the liquid-solid region. The density profiles showed strong discrete layering of the fluid near the solid-liquid interface, with more pronounced layering at lower temperatures and for mixtures of short chains.
Article
Engineering, Chemical
Ian H. Bell, Ulrich K. Deiters, Andreas Jager
Summary: In this work, it is demonstrated that tracing the vapor-liquid equilibria for binary mixtures can provide all the necessary information to obtain the three-phase line, including when one component is supercritical. The authors also demonstrate the automatic construction of an isothermal pressure-composition figure, enabled by solving for the three-phase state.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Engineering, Chemical
Ian H. Bell, Ulrich K. Deiters, Allan M. M. Leal
Summary: This work utilizes advanced numerical techniques to efficiently compute thermodynamic properties, avoiding the tedious process of symbolic differentiation and enabling faster development of new models.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2022)
Article
Engineering, Chemical
Ian H. Bell, Ulrich K. Deiters
Summary: Superancillary equations have been developed for the PC-SAFT equation of state, which accurately represent densities for vapor-liquid equilibria of nonpolar pure fluids. These equations outperform iterative calculations in terms of accuracy and speed, and they are reliable over the entire temperature range. The functions have been made user-friendly by packaging them into a Python package available on PYPI.
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2023)
Article
Chemistry, Physical
Ulrich K. Deiters, Richard J. Sadus
Summary: This study reports a novel molecular simulation method for accurately determining solid-liquid equilibria at different pressures. The results show that this new method yields more accurate predictions compared to existing methods, highlighting its importance in understanding interatomic interactions responsible for solid-liquid equilibria.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Ulrich K. Deiters, Richard J. Sadus
Summary: This study reports an intermolecular potential for molecular hydrogen that incorporates two-body and three-body interactions, validated by experimental data and Monte Carlo simulations. The addition of three-body interactions significantly improves the accuracy of predictions for vapor-liquid equilibria and critical properties. Moreover, the inclusion of quantum effects narrows the phase envelope and lowers the critical temperature. The findings highlight the importance of considering three-body interactions in understanding the phase behavior of hydrogen.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
Ulrich K. Deiters, Richard J. Sadus
Summary: This article reports a novel molecular simulation technique for predicting the triple point temperature of atomic fluids with high accuracy. The study shows that the triple point is greatly influenced by the choice of different interactions. Improving the theoretical understanding of triple points is important for scientific research and metrology as it relates fundamental constants to temperature scales.
