Article
Chemistry, Physical
Yu Ying He, Li Guang Jiao, Aihua Liu, Henry E. Montgomery, Yew Kam Ho
Summary: The static multipole polarizabilities of a hydrogen atom confined in an impenetrable spherical box and interacting with a screened Coulomb potential are calculated in this study. The results obtained with high precision help resolve discrepancies between previous predictions and provide insights into the critical behavior of the system under varying confinement radius and screening parameter. A scaling law for the multipole polarizabilities, based on the nuclear charge and electron reduced mass, is proposed. This scaling law is then used to investigate the spatially confined positronium atom in a screened Coulomb potential using a reduced one-electron model. The results are in good agreement with previous estimates, although it is suggested that an effective two-electron model should be used for the confined positronium atom with small confinement radius.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2023)
Article
Mathematics, Applied
Wenxu Ge, Weiping Li, Tianze Wang
Summary: In this paper, relations between Gauss sums of order 3 are provided. As an application, the number of solutions for some cubic diagonal equations is given. These results generalize previous findings by Hong-Zhu and solve the sign problem raised by Zhang-Zhang.
Article
Optics
Li Guang Jiao, Xiao Hu Ji, Zi Xi Hu, Aihua Liu, H. E. Montgomery, Yew Kam Ho
Summary: The study investigates s-wave resonance in an exponential cosine screened Coulomb potential using a uniform complex-scaling generalized pseudospectral method. It finds a gap in the screening parameter before the ground state transforms into a well-defined shape resonance above the autoionization threshold. The critical value for this transformation is determined, and it is speculated that the system behavior in the gap may involve the transformation of bound states into negative-energy virtual states and below-threshold shape resonances. Resonance positions and widths are calculated for screening parameters larger than the critical value, showing high precision and comparability with previous predictions. Trajectories of poles of the S-matrix in both complex energy and momentum planes are obtained.
EUROPEAN PHYSICAL JOURNAL D
(2021)
Article
Physics, Multidisciplinary
Abdelmadjid Maireche
Summary: In this work, approximate and analytical solutions for the deformed Klein-Gordon equation with an interaction potential are presented, utilizing the Greene and Aldrich approximation to overcome centrifugal barriers. This study explores the noncommutative symmetries in relativistic 3-dimensional space and provides insights for calculating energy levels of neutral atoms. The newly proposed potential shows improved precision compared to traditional quantum mechanics methods.
Article
Physics, Multidisciplinary
E. P. Inyang, E. Omugbe, M. Abu-Shady, E. S. William
Summary: In this study, the modified Kratzer potential and Yukawa potential were used to solve the Schrodinger equation, and the Nikiforov-Uvarov method was employed to determine the energy equation and total normalized wave function. The Shannon entropy, Fisher information, and expectation values were analyzed for the low-lying states. It was found that the inequalities for Shannon entropy and Fisher information were satisfied, and the Heisenberg uncertainty relation was validated through numerical calculations.
EUROPEAN PHYSICAL JOURNAL PLUS
(2023)
Article
Physics, Multidisciplinary
Lei Xu, Li Guang Jiao, Aihua Liu, Henry E. Montgomery Jr., Yew Kam Ho, Stephan Fritzsche
Summary: The energy spectra and asymptotic behaviors of the radial screened Coulomb potential are investigated. Numerical calculations show significant discrepancies with previous predictions. Based on the Hellmann-Feynman theorem, the asymptotic behavior of the energy spectra for small screening parameters is analyzed, and an empirical reciprocal law for energies when the screening parameter approaches infinity is proposed.
Article
Computer Science, Interdisciplinary Applications
Nail A. Gumerov, Shoken Kaneko, Ramani Duraiswami
Summary: In this study, a new fast method called Quadrature to Expansion (Q2X) is proposed for the analytical generation of multipole expansion coefficients in boundary element methods accelerated by fast multipole methods (FMM). The method efficiently computes the moments and integrates them into FMM to control the error. It is developed for boundary element methods involving the Laplace Green's function in R3 and is validated through numerical tests.
JOURNAL OF COMPUTATIONAL PHYSICS
(2023)
Article
Mathematics, Applied
Junpu Li, Yan Gu, Qing-Hua Qin, Lan Zhang
Summary: This study presents a modified multilevel fast multipole algorithm that expands the levels of the modified fast multipole algorithm through recursive calculation and correction. The algorithm significantly reduces the total storage space of sparse matrices while maintaining efficiency. The algorithm demonstrates O(N) operation efficiency and storage complexity for three-dimensional potential models.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Eric Ouma Jobunga
Summary: In this study, a symmetry-dependent analytical all-electron potential for the helium atom is proposed. The potential is derived using an alternative multipole expansion, a variational technique, and a mean-field approximation. The results are in reasonable agreement with literature values.
RESULTS IN PHYSICS
(2022)
Article
Physics, Multidisciplinary
M. Napsuciale, S. Rodriguez
Summary: This study presents a phenomenological analysis of the bound eigenstates and eigenvalues solution of the Yukawa potential, revealing that ε(nl)(δ) increases with l, leading to level crossings for n≥4. By utilizing the Pade approximants technique, the convergence radius of the Taylor series is expanded, allowing for high precision calculations of eigenvalues across the full range of δ values. The solutions provide insights into the phenomenology of dark matter bound states in dark gauge theories with a light dark mediator.
PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Etido P. Inyang, Funmilayo Ayedun, Efiong A. Ibanga, Kolawole M. Lawal, Ituen B. Okon, Eddy S. William, Omugbe Ekwevugbe, Clement A. Onate, Akaninyene D. Antia, Effiong O. Obisung
Summary: In this study, approximate analytical solutions to the N-dimensional Schrödinger equation were obtained for diatomic molecules with specific potentials. The energy spectrum and thermodynamic properties of the molecules were investigated and compared with experimental results to validate the accuracy of the study.
RESULTS IN PHYSICS
(2022)
Article
Mathematics, Applied
Hu Bin, Hu Zongjun, Li Cong, Niu Zhongrong, Li Xiaobao
Summary: A novel fast multipole boundary element method (FM-BEM) is introduced for 2-D potential problems, utilizing linear and three-node quadratic elements. Complex notation is used to simplify computational formulations in the boundary integral equations, resulting in higher accuracy and better computational efficiency.
COMPUTERS & MATHEMATICS WITH APPLICATIONS
(2021)
Article
Physics, Multidisciplinary
Obu J. Abebe, Okoi P. Obeten, Uduakobong S. Okorie, Akpan N. Ikot
Summary: The study focused on analyzing the bound-state solutions of the spin and pseudospin limits of the Dirac equation using the Nikiforov-Uvarov method and an appropriate approximation scheme. By adjusting potential parameters, six special potentials were evaluated and found to be in good agreement with existing literature. The behavior of diatomic molecules under the (GMP+CYP) potential was also investigated and compared.
PRAMANA-JOURNAL OF PHYSICS
(2021)
Article
Physics, Atomic, Molecular & Chemical
Xi Wang, Zishi Jiang, Sabyasachi Kar, Yew Kam Ho
Summary: This study investigates the singly-excited and doubly-excited 1,3Po states of screened-heliumlike atoms from Li+ to Ne8+ using exponential cosine-screened Coulomb potentials. The correlations between charged particles are represented using pseudo-random-parameters dependent correlated exponential wave functions. Results show a total of 9 P-wave resonances in each screened-system, as well as the presentation of singly-excited states and doubly-excited 1,3Po states in ECS-heliumlike systems for the first time in the literature.
ATOMIC DATA AND NUCLEAR DATA TABLES
(2022)
Article
Mathematics, Applied
Matthias Kirchhart, Donat Weniger
Summary: The study introduces simplified formulas for computing the Newton potential of polynomial distributions, implemented in a C++ library for arbitrary precision arithmetic calculations. These results can be combined with fast multipole methods to evaluate the Newton potential of more general, non-polynomial densities.
JOURNAL OF NUMERICAL MATHEMATICS
(2022)
Article
Computer Science, Interdisciplinary Applications
Usman Riaz, E. Seegyoung Seol, Robert Hager, Mark S. Shephard
Summary: The accurate representation and effective discretization of a problem domain into a mesh are crucial for achieving high-quality simulation results and computational efficiency. This work presents recent developments in extending an automated tokamak modeling and meshing infrastructure to better support the near flux field following meshing requirements of the XGC Gyro-kinetic Code.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Zhenglu Li, Gabriel Antonius, Yang-Hao Chan, Steven G. Louie
Summary: This article presents a workflow for practical calculations of electron-phonon coupling and includes the effect of many-electron correlations using GW perturbation theory. The workflow combines different software packages to enable accurate calculations at the level of quasiparticle band structures.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Akihiro Koide, Sara Rabouli, Pierre Le Meur, Sylvain Tricot, Philippe Schieffer, Didier Sebilleau, Calogero R. Natoli
Summary: We present the MsSpec Atomic Scattering Amplitude Package (MASAP), which includes a computation program and a graphical interface for generating atomic scattering amplitude (ASA). The study investigates the applicability of plane wave (PW) and curved spherical wave (SW) scattering in describing electron propagation. The results show that the imaginary part of the optical potential enhances the elastic scattering in the forward direction but causes damping effects in other directions.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
A. Bagci, Gustavo A. Aucar
Summary: The electron repulsion integrals over Slater-type orbitals with non-integer principal quantum numbers are investigated in this study. These integrals are important in calculations of many-electron systems. New relationships free from hyper-geometric functions are derived to simplify the calculations. With the use of auxiliary functions and straightforward recurrence relationships, these integrals can be efficiently computed, providing initial conditions for the evaluation of expectation values and potentials.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Andrzej Daniluk
Summary: RHEED_DIFF_2D is an open-source software for qualitative numerical simulations of RHEED oscillation intensity changes with layer deposition, used for interpreting heteroepitaxial structures under different scattering crystal potential models.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Niklas Kuehl, Hendrik Fischer, Michael Hinze, Thomas Rung
Summary: The article presents a strategy and algorithm for simulation-accompanying, incremental Singular Value Decomposition (SVD) for time-evolving, spatially parallel discrete data sets. The proposed method improves computational efficiency by introducing a bunch matrix, resulting in higher accuracy and practical applicability.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Jose M. Rodriguez-Borbon, Xian Wang, Adrian P. Dieguez, Khaled Z. Ibrahim, Bryan M. Wong
Summary: This paper presents an open-source software package called TRAVOLTA for massively parallelized quantum optimal control calculations on GPUs. The TRAVOLTA package is an improvement on the previous NIC-CAGE algorithm and incorporates algorithmic improvements for faster convergence. Three different variants of GPU parallelization are examined to evaluate their performance in constructing optimal control fields in various quantum systems. The benchmarks show that the GPU-enhanced TRAVOLTA code produces the same results as previous CPU-based algorithms but with a speedup of more than ten times. The GPU enhancements and algorithmic improvements allow large quantum optimal control calculations to be efficiently executed on modern multi-core computational hardware.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Weijie Hua
Summary: This work introduces a program called MCNOX for computing and analyzing ultrafast nonlinear X-ray spectra. It is designed for cutting-edge applications in photochemistry/photophysics enabled by X-ray free-electron lasers and high harmonic generation light sources. The program can calculate steady-state X-ray absorption spectroscopy and three types of ultrafast nonlinear X-ray spectra, and it is capable of identifying major electronic transitions and providing physical and chemical insights from complex signals.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Leandro Benatto, Omar Mesquita, Lucimara S. Roman, Rodrigo B. Capaz, Graziani Candiotto, Marlus Koehler
Summary: Photoluminescence Quenching Simulator (PLQ-Sim) is a user-friendly software for studying the dynamics of photoexcited states at the interface between organic semiconductors. It provides important information on organic photovoltaic and photothermal devices and calculates transfer rates and quenching efficiency.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Dongming Li, James Kestyn, Eric Polizzi
Summary: This study introduces a practical and efficient approach to calculate the all-electron full potential band structure in real space using a finite element basis. Instead of the k-space method, this method solves the Kohn-Sham equation self-consistently within a larger finite system enclosing the unit-cell. Non-self-consistent calculations are then performed in the Brillouin zone to obtain the band structure results, which are found to be in excellent agreement with the pseudopotential k-space method. Furthermore, the study successfully observes the band bending of core electrons.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
R. Kleiber, M. Borchardt, R. Hatzky, A. Koenies, H. Leyh, A. Mishchenko, J. Riemann, C. Slaby, J. M. Garcia-Regana, E. Sanchez, M. Cole
Summary: This paper describes the current state of the EUTERPE code, focusing on the implemented models and their numerical implementation. The code is capable of solving the multi-species electromagnetic gyrokinetic equations in a three-dimensional domain. It utilizes noise reduction techniques and grid resolution transformation for efficient computation. Additionally, various hybrid models are implemented for comparison and the study of plasma-particle interactions. The code is parallelized for high scalability on multiple CPUs.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Pengliang Yang
Summary: This paper presents an open source software called SMIwiz, which combines seismic modelling, reverse time migration, and full waveform inversion into a unified computer implementation. SMIwiz supports both 2D and 3D simulations and provides various computational recipes for efficient calculation. Its independent processing and batchwise job scheduling ensure scalability, and its viability is demonstrated through applications on benchmark models.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Christian Tantardini, Miroslav Ilias, Matteo Giantomassi, Alexander G. Kvashnin, Valeria Pershina, Xavier Gonze
Summary: Material discovery has been an active research field, and this study focuses on developing pseudopotentials for actinides and super-heavy elements. These pseudopotentials are crucial for accurate first-principles calculations and simulations.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
S. Blanes, F. Casas, C. Gonzalez, M. Thalhammer
Summary: This paper explores the extension of modified potential operator splitting methods to specific classes of nonlinear evolution equations. Numerical experiments confirm the advantages of the proposed fourth-order modified operator splitting method over traditional splitting methods in dealing with Gross-Pitaevskii systems.
COMPUTER PHYSICS COMMUNICATIONS
(2024)
Article
Computer Science, Interdisciplinary Applications
Siegfried Kaidisch, Thomas U. Hilger, Andreas Krassnigg, Wolfgang Lucha
Summary: Motivated by a use case in theoretical hadron physics, this paper revisits an application of a pole-sum fit to dressing functions of a confined quark propagator. Specifically, it investigates approaches to determine the number and positions of singularities closest to the origin for a function known numerically on a specific grid on the positive real axis. Comparing the efficiency of standard techniques to a pure artificial-neural-network approach and a combination of both, it finds that the combined approach is more efficient. This approach can be applied to similar situations where the positions of poles need to be estimated quickly and reliably from real-axis information alone.
COMPUTER PHYSICS COMMUNICATIONS
(2024)