Article
Computer Science, Software Engineering
Rohan Sawhney, Dario Seyb, Wojciech Jarosz, Keenan Crane
Summary: This paper introduces a method for solving partial differential equations with spatially varying coefficients. By extending the walk on spheres algorithm from volumetric rendering to variable-coefficient problems, the exact solution for problems with detailed geometry and intricate coefficients can be obtained. This method does not require discretization of the problem and offers advantages such as unbiased Monte Carlo estimators and the ability to evaluate the solution at any point without solving a global system of equations.
ACM TRANSACTIONS ON GRAPHICS
(2022)
Article
Chemistry, Physical
Eugene A. Ustinov
Summary: In this study, a binary mixture is simulated at various temperatures using an extended version of the grand canonical kinetic Monte Carlo method. The focus is on understanding the thermodynamic properties of binary liquids, gases, and gas-liquid mixtures from a comprehensive perspective. The approach includes considering thermodynamic functions such as chemical potentials, Gibbs free energy, and entropy. The results show a high degree of accuracy and reproducibility when compared to experimental data, with the developed approach able to accurately reproduce the pressure-composition diagrams.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
Seher Karakuzu, Benjamin Cohen-Stead, Cristian D. Batista, Steven Johnston, Kipton Barros
Summary: In this study, a class of Hubbard-Stratonovich transformations suitable for quantum Monte Carlo simulations of Hubbard interactions is considered. A tunable parameter p allows for a continuous variation from a discrete Ising auxiliary field (p = infinity) to a compact auxiliary field that couples to electrons sinusoidally (p = 0). Testing on the single-band square and triangular Hubbard models shows that the severity of the sign problem decreases systematically with increasing p. However, selecting a finite p enables continuous sampling methods such as Langevin or Hamiltonian Monte Carlo. The tradeoffs between various simulation methods are explored through numerical benchmarks.
Article
Quantum Science & Technology
Sergey Bravyi, Giuseppe Carleo, David Gosset, Yinchen Liu
Summary: The main objective of this study is to sample bit strings from a given distribution by exploring the relationship between the inverse spectral gap of a Hamiltonian and the mixing time of a Markov Chain. The proposed sampling algorithm, based on the fixed-node Hamiltonian construction, shows a faster mixing time compared to the standard Metropolis-Hastings Markov chain.
Article
Multidisciplinary Sciences
Zhen Zhang, Jun Ding, Evan Ma
Summary: Plastic flow in metallic glasses is not caused by identifiable local defect regions. Through a realistic model, we found that shear transformations involve only a small percentage of atoms and their locations and distribution vary under different mechanical loading conditions.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Multidisciplinary Sciences
R. Mondaini, S. Tarat, R. T. Scalettar
Summary: The sign problem is a fundamental limitation in simulations of strongly correlated matter. In this study, the quantitive connection between the sign problem in determinant quantum Monte Carlo (QMC) and quantum critical behavior is demonstrated through simulations of several well-understood models. A reinterpretation of the low average sign in the Hubbard model is proposed, relating it to the onset of pseudogap behavior and exotic superconductivity.
Article
Physics, Fluids & Plasmas
Akiho Tani, Yutaro Tanii, Kyoka Ishiyama, Shusaku Harada, Hisao Satoh
Summary: Monte Carlo simulations were used to investigate the structural change of hard sphere-platelet mixtures under different particle sizes. The results showed that the size and density of the particles have different effects on the structural transitions of platelet and spherical particles.
Article
Materials Science, Multidisciplinary
Massimo Boninsegni
Summary: Theoretical studies through computer simulations on metastable liquid mixtures of parahydrogen and orthodeuterium show no reduced propensity for crystallization compared to pure liquid parahydrogen, and no demixing of the two species as a precursor of crystallization.
RESULTS IN PHYSICS
(2021)
Article
Physics, Multidisciplinary
Tongzhou Zhao, Ajit C. Balram, J. K. Jain
Summary: Pairing of composite fermions at filling factors 1/2 and 1/4 induces non-Abelian fractional quantum Hall states.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Physical
Abdelhafid Ait Blal, Dusan Stosic, Philippe Bazin, Alexandre Vimont, Arnaud Travert
Summary: This study presents a new method for investigating the mass transport properties of acidic zeolite-based materials. By combining gravimetric analysis and infrared spectroscopy, diffusion within the various components of the material can be monitored and distinguished. The method was applied to a mechanical mixture of FAU and MFI zeolites, allowing for the identification of diffusion domains with high and low effective diffusion rate constants.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Tolson H. Bell, Jerrell M. Cockerham, Clayton M. Mizgerd, Melita F. Wiles, Christian R. Scullard
Summary: We propose a method for computing transition points of the random cluster model using a generalization of the Newman-Ziff algorithm. The method is easy to implement and works for real cluster weight q > 0. It allows for obtaining results for an arbitrary number of values of q within a single simulation. However, the accuracy is reduced for q > 1 on large lattices. Nonetheless, accurate estimates of critical points in two dimensions can be obtained by sampling the critical polynomial, as demonstrated in this study on the square lattice and the unsolved non-planar square matching lattice.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Chemistry, Physical
Suryadip Bhattacharjee, Jhumpa Adhikari
Summary: Carvacrol, a naturally occurring aromatic compound with medicinal properties, lacks comprehensive experimental VLE data, leading to the use of molecular simulation and force field techniques to predict coexistence properties at elevated temperatures. Critical state properties and acentric factor for carvacrol were determined in this study. Molecular-level investigation of the liquid phase structure and hydrogen-bonding extent was also conducted.
Article
Mathematics, Interdisciplinary Applications
Tahir Cosgun, Murat Sari
Summary: This study introduces a new algorithm called the reversed fixed point iteration method (RFPIM) to uncover the unstable equilibrium positions of a nonlinear system, which has been proven to have various advantages over conventional methods through mathematical analysis and numerical observations with illustrative examples.
CHAOS SOLITONS & FRACTALS
(2021)
Review
Multidisciplinary Sciences
Najda Villefranque, Frederic Hourdin, Louis d'Alencon, Stephane Blanco, Olivier Boucher, Cyril Caliot, Christophe Coustet, Jeremi Dauchet, Mouna El Hafi, Vincent Eymet, Olivier Farges, Vincent Forest, Richard Fournier, Jacques Gautrais, Valery Masson, Benjamin Piaud, Robert Schoetter
Summary: This article reviews the scientific advances in urban climate modeling and highlights the potential of combining mathematics, physics, computer, and engineering sciences in this field. Simulating coupled heat transfer in complex urban geometries allows for a better understanding, prediction, and improvement of urban energy performance.
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
Physics, Multidisciplinary
Zheng Ma, Enrique Lomba, Salvatore Torquato
PHYSICAL REVIEW LETTERS
(2020)
Article
Thermodynamics
Diego Gonzalez-Salgado, Jacobo Troncoso, Enrique Lomba
FLUID PHASE EQUILIBRIA
(2020)
Article
Thermodynamics
Encarnacion Garcia Perez, Diego Gonzalez-Salgado, Enrique Lomba
Summary: The excess enthalpy and excess volume of binary systems containing methanol, ethanol, 1-propanol, 2-propanol, tert-butanol, and water were studied using MD simulations at 298.15 K. The new parameterization allowed for an appropriate description of the excess thermodynamics, but the models did not adequately reproduce the changes in maximum density temperature induced by alcohol concentration. The simulated decrease in the maximum density temperature with increasing alcohol concentration contrasts with experimental results.
FLUID PHASE EQUILIBRIA
(2021)
Article
Chemistry, Physical
Carolina Cruz, Svyatoslav Kondrat, Enrique Lomba, Alina Ciach
Summary: Ionic liquid-solvent mixtures in slit-shaped nanopores wider than a few ion diameters can undergo a capillary ionization transition, where the pores spontaneously ionize or deionize upon infinitesimal changes of temperature, slit width, or voltage. Interestingly, a voltage applied to a pore may induce capillary ionization followed by re-entrant deionization as the voltage increases. These ionization transitions can result in sharp jumps in accumulated charge and stored energy, which may have useful applications in energy storage and heat-to-energy conversion.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Carolina Cruz, Enrique Lomba, Alina Ciach
Summary: This study investigates the concentration fluctuations in an electrolyte confined between electrodes formed by parallel graphene layers. The effect of proximity to the demixing transition on electric double layers is analyzed and compared to theoretical predictions. The results show that lowering temperature enhances capacitance for dilute ionic solutions near the demixing transition, while higher ionic concentrations have a less noticeable effect. Additionally, the shape of the capacitance changes, exhibiting a maximum at the potential of zero charge and symmetric maxima for positive and negative voltages.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Physics, Multidisciplinary
Murilo S. Marques, Enrique Lomba, Eva G. Noya, Diego Gonzalez-Salgado, Marcia Barbosa
Summary: This paper investigates the anomalous behavior of the temperature of maximum density of water influenced by the two-site model of tert-butanol. The simple model is able to reproduce the anomaly at low alcohol mole fractions, correlated with changes in the local structure of water.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2021)
Article
Chemistry, Physical
Giuseppe Pellicane, Enrique Lomba, Franz Saija
Summary: This study uses theoretical and Monte Carlo computer simulations to investigate the thermodynamic and structural properties of a binary mixture of nonadditive hard-disks. The results show that the microscopic theory is able to accurately predict the equation of state and radial distribution functions of the system. This is an important milestone in understanding the self-assembly phenomena of binary mixtures of colloidal particles adsorbed at the interface.
PHYSICS AND CHEMISTRY OF LIQUIDS
(2022)
Article
Chemistry, Physical
D. Gonzalez-Salgado, J. Troncoso, E. Lomba
Summary: The temperature of maximum density of aqueous solutions of tert-butanol has been experimentally determined, and molecular dynamics simulations have been performed to study the effect of pressure and temperature on the density anomaly. The results show that the addition of tert-butanol promotes the low density water structure, and this promotion is influenced by pressure and temperature.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Thermodynamics
D. Gonzalez-Salgado, E. G. Noya, E. Lomba
Summary: This study provides a quantitative explanation for the existence and dependence of the temperature of maximum density (T-MD) on pressure in water. The analysis reveals that the temperature dependence of low and high density water states, as well as the variation of mole fractions with pressure, play crucial roles in the T-MD phenomenon.
FLUID PHASE EQUILIBRIA
(2022)
Article
Chemistry, Physical
Paula Gomez-Alvarez, Eva G. Noya, Enrique Lomba
Summary: The study aims to obtain a molecular understanding of water and alcohol adsorption in pure-silica zeolites using molecular simulation techniques. The research found differences in adsorption behavior between MFI and MEL zeolites, despite their structural similarities, which are attributed to the underlying molecular interactions.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Biochemical Research Methods
Luciana Melina Luque, Carlos Manuel Carlevaro, Camilo Julio Llamoza Torres, Enrique Lomba
Summary: This study presents a multiagent-based model that captures the interactions between different types of cells with their microenvironment, and enables the analysis of the emergent global behavior during tissue regeneration and tumor development. By tuning the system with the characteristics of the individual patients, the model reproduces a variety of spatial patterns of tissue regeneration and tumor growth, resembling those found in clinical imaging or biopsies. In the clinical context, the model is able to predict the recurrence of a hepatocellular carcinoma after a 70% partial hepatectomy.
PLOS COMPUTATIONAL BIOLOGY
(2023)
Article
Chemistry, Physical
D. Gonzalez-Salgado, E. G. Noya, E. Lomba
Summary: The effect of non polar solutes on the temperature of maximum density of water, TMD, is analyzed in detail by means of molecular simulations over an ample pressure interval ranging from negative to very high pressures. The study finds that non polar solutes decrease the TMD at pressures below-200 bar and increase the TMD at higher pressures. The change in TMD can be attributed to the competition between low density and high density water states.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Editorial Material
Physics, Condensed Matter
Marcia C. Barbosa, Ana Laura Benavides, Manuel Carlevaro, Gerhard Kahl, Enrique Lomba
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Physics, Multidisciplinary
Johan S. Hoye, Enrique Lomba
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2020)
Article
Physics, Fluids & Plasmas
Enrique Lomba, Jean-Jacques Weis, Leandro Guisandez, Salvatore Torquato
