Article
Materials Science, Multidisciplinary
Yanan Sun, Jin Lyu, Jian-Ping Lv
Summary: This study investigates the surface critical behavior at an emergent superfluid-Mott insulator critical point using worm Monte Carlo simulations. The results provide evidence for special transitions and extraordinary-log universality in the system.
Article
Chemistry, Physical
Tina N. Mihm, William Z. Van Benschoten, James J. Shepherd
Summary: A new approach using low-cost calculations was developed to find a twist angle that matches the coupled cluster doubles energy in a finite unit cell. The method was shown to have comparable accuracy with exact methods beyond coupled cluster doubles theory. Additionally, for small system sizes, the same twist angle can be found by comparing energies directly, suggesting a potential route towards twist angle selection.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Computer Science, Interdisciplinary Applications
Robin Fingerhut, Gabriela Guevara-Carrion, Isabel Nitzke, Denis Saric, Joshua Marx, Kai Langenbach, Sergei Prokopev, David Celny, Martin Bernreuther, Simon Stephan, Maximilian Kohns, Hans Hasse, Jadran Vrabec
Summary: The new version 4.0 of the molecular simulation tool ms2 introduces two additional potential functions and enhances computational efficiency. It also provides new properties, functionalities, and features, such as thermodynamic factor, thermal diffusion coefficients, and non-Gaussian parameters, to improve the application-oriented thermodynamic properties and microscopic structure analysis.
COMPUTER PHYSICS COMMUNICATIONS
(2021)
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
Physics, Multidisciplinary
Francesco Parisen Toldin
Summary: The study reveals the existence of a special phase transition and an extraordinary phase with logarithmically decaying correlations in the presence of a bidimensional surface in the three-dimensional Heisenberg universality class. These findings help explain some recent puzzling results on the boundary critical behavior of quantum spin models.
PHYSICAL REVIEW LETTERS
(2021)
Article
Mathematics, Applied
M. Ganesh, B. Reyes
Summary: The paper investigates a class of physical processes modeled by the Allen-Cahn (A-C) partial differential equation (PDE) evolutionary system with uncertainties in the initial state and the A-C PDE. A hybrid computational model is developed to efficiently compute statistical moments of the numerical counterparts of the A-C stochastic processes by using finite element method, high-order digital nets sampling, and interplay of discretization parameters. The hybrid framework demonstrates marked efficiency compared to standard methods in handling two- and three-dimensional space, and high stochastic dimensional A-C examples.
JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS
(2022)
Article
Chemistry, Multidisciplinary
Yaowei Hu, Matthieu Picher, Marlene Palluel, Nathalie Daro, Eric Freysz, Laurentiu Stoleriu, Cristian Enachescu, Guillaume Chastanet, Florian Banhart
Summary: The unusual expansion dynamics of individual spin crossover nanoparticles were investigated using ultrafast transmission electron microscopy. Upon exposure to nanosecond laser pulses, the particles exhibited significant length oscillations during and after expansion. The observed oscillation period of 50-100 ns was similar to the time required for the particles to transition between low-spin and high-spin states. Monte Carlo calculations incorporating elastic and thermal coupling between molecules within a crystalline spin crossover particle were able to explain the observed length oscillations. The system underwent repeated transitions between the two spin states until relaxation in the high-spin state occurred due to energy dissipation.
Article
Chemistry, Physical
Weiqi Wang, Xiangyue Liu, Jesus Perez-Rios
Summary: An approach based on ab initio statistical mechanics is demonstrated for autoconstructing complex reaction networks, with oxygen activation on Ag-4 as a model reaction. It has been shown that this method is suitable for automatized construction of reaction networks and can be used for studying structural effects and reaction rates, especially for non-well-studied reactions.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Physics, Multidisciplinary
Volker Dohm, Stefan Wessel, Benedikt Kalthoff, Walter Selke
Summary: Researchers have verified recent analytic predictions derived from anisotropic phi(4) theory and conformal field theory regarding the critical free energy amplitude of finite anisotropic systems in the two-dimensional Ising universality class through high-precision Monte Carlo simulations, finding remarkable agreement between the experimental data and the theoretical predictions. This study supports the validity of multiparameter universality and refutes the validity of two-scale-factor universality, while also comparing the results with exact results in the three-dimensional phi(4) model with planar anisotropy and briefly discussing the critical Casimir amplitude.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Physics, Applied
A. Gudyma, Iu. Gudyma
Summary: The study investigates the relationship between one-dimensional molecular chains with two single-particle degenerate states, establishes a connection with the Ising model with phononic interactions, and explores the properties of the model using a transfer-matrix method. The role of state degeneracy and phononic interactions is explicitly stated, and the existence of two peaks in the specific heat capacity behavior is demonstrated.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Physics, Nuclear
K. Hebeler, V. Durant, J. Hoppe, M. Heinz, A. Schwenk, J. Simonis, A. Tichai
Summary: Three-nucleon (3N) interactions are essential for accurately solving the nuclear many-body problem, but accurately considering these forces is computationally challenging, so approximate treatments are often used. The method of normal ordering provides a powerful tool for including 3N interactions systematically and efficiently, but traditional frameworks require a large single-particle basis, often leading to truncation of 3N matrix elements. This limitation is overcome by a novel normal-ordering framework performed directly in a Jacobi basis, allowing for calculations of ground-state energies and charge radii of heavy nuclei.
Article
Multidisciplinary Sciences
Elizabeth R. Belden, Nikolaos K. Kazantzis, Christopher M. Reddy, Hauke Kite-Powell, Michael T. Timko, Eduardo Italiani, Dudley R. Herschbach
Summary: The study examines the feasibility and potential impacts of using hydrothermal liquefaction of waste plastics as fuel for self-powered ocean cleanup. A thermodynamic analysis shows that this method has the energy potential to power both the cleanup process and the ship. The efficiency of cleanup operations is mainly dependent on the number of cleanup devices deployed in the Great Pacific Garbage Patch.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Thermodynamics
Nathan Barros de Souza, Joyce Tavares Lopes, Luis Fernando Mercier Franco
Summary: Perturbation theory plays a key role in the development of new equations of state, with approximations necessary for calculations. A new equation of state has been proposed based on a unique reference fluid and perturbed potential definition. Validity of this approximation was investigated using Monte Carlo simulations, and perturbed molar Helmholtz free energy was calculated for potential equation of state improvement.
FLUID PHASE EQUILIBRIA
(2021)
Article
Physics, Fluids & Plasmas
Marcio Sampaio Gomes-Filho, Fernando Albuquerque Oliveira, Marco Aurelio Alves Barbosa
Summary: A computational model is proposed to investigate drug delivery systems with erosion and diffusion mechanisms. The crossover point between these mechanisms is estimated, and a phenomenological expression for the characteristic release in terms of size and erosion rate is proposed.
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)