Article
Optics
Vladimir A. Yerokhin, Vojtech Patkos, Krzysztof Pachucki
Summary: We performed ab initio calculations of the QED effects for the 2 3S and 2 3P states of He-like ions at the order of m alpha 7. By combining the computed effects with previously calculated energies, the theoretical accuracy has been improved significantly. The obtained results for the transition energies agree well with experiment and previous calculations, while some inconsistency is observed for the ionization energies, possibly related to the theoretical-experimental discrepancy in helium ionization energies.
Article
Optics
Michal Silkowski, Krzysztof Pachucki, Jacek Komasa, Mariusz Puchalski
Summary: We perform highly accurate calculations of the leading-order QED correction to the ground electronic state of molecular hydrogen. Numerical results are obtained for a grid of the internuclear distances R = 0-10 a.u. with the relative precision of about 10-8. The major numerical uncertainty of previous QED results has been eliminated. Nevertheless, the discrepancy with measurements in HD at the level of 1.9 a persists.
Article
Physics, Multidisciplinary
Krzysztof Pachucki, Vladimir A. Yerokhin
Summary: This study examines how the transverse electromagnetic interaction between two pointlike particles is modified when one of the particles has a finite size. It is found that the traditional Breit approximation is not sufficient, and the interaction should be treated within the framework of Quantum Electrodynamics (QED). The complete QED formula for the finite-size nuclear recoil is derived, taking into account the coupling strength parameter Z alpha. Numerical calculations are performed for a range of Z values and validated against the oZ alpha thorn 5 contribution. Comparison with the Z alpha expansion reveals the significance of the oZ alpha thorn 6 term, which is linear in the nuclear radius and numerically dominates over the lower-order oZ alpha thorn 5 term.
PHYSICAL REVIEW LETTERS
(2023)
Article
Optics
Vladimir A. Yerokhin, Vojtech Patkos, Krzysztof Pachucki
Summary: This paper presents a calculation of two-electron QED effects to all orders in the nuclear binding strength parameter Z alpha for the ground and n = 2 excited states of helium-like ions. The higher-order QED effects of order m alpha 7 and higher are identified after subtracting the first terms of the Z alpha expansion from the all-order results. The most accurate theoretical predictions for the ground and non-mixing n = 2 states of helium-like ions with Z = 5-30 are obtained by combining the higher-order remainder with the results complete through order m alpha 6 from a previous study.
Article
Physics, Multidisciplinary
A. Malyshev, D. A. Glazov, Y. S. Kozhedub, I. S. Anisimova, M. Y. Kaygorodov, V. M. Shabaev, I. I. Tupitsyn
Summary: This study overcomes the obstacles in calculations for Be-like xenon by working on QED perturbation theory for quasidegenerate states, resulting in the most accurate theoretical predictions for binding and excitation energies. The approach takes into account the contributions of all Feynman diagrams up to the second order and evaluates many-electron QED effects rigorously within the extended Funy picture framework.
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
V. A. Zaytsev, A. V. Malyshev, V. M. Shabaev
Summary: An ab initio method based on a complex-scaling approach for rigorous QED description of autoionizing states is developed. Nonperturbative treatment of autoionizing state binding energies in alpha Z, including all the many-electron QED contributions up to the second order, is achieved. Higher-order electron correlation, nuclear recoil, and nuclear polarization effects are also considered. The proposed formalism is applied to LL resonances in helium-like argon and uranium, resulting in the most accurate theoretical predictions for binding energies.
Article
Multidisciplinary Sciences
Romain N. Soguel, Andrey V. Volotka, Dmitry A. Glazov, Stephan Fritzsche
Summary: The redefined vacuum approach is a powerful tool in deriving formulas within the bound-state QED perturbation theory, particularly for single particle excitation. By deducing many-electron contributions from simple one-electron QED diagrams, the method allows for straightforward derivation and identification of gauge-invariant subsets based on the gauge invariance of the diagrams.
Article
Chemistry, Physical
Ayaki Sunaga, Maen Salman, Trond Saue
Summary: We report the implementation of effective quantum electrodynamics (QED) potentials for all-electron four-component relativistic molecular calculations. The potentials are available for two-component calculations through proper picture-change transformation. The study demonstrates the significance of picture-change errors and presents the implementation of Uehling potential for vacuum polarization and two effective potentials for electron self-energy. Sample applications include observing QED effects in the AuCN molecule, bond length expansions in van der Waals dimers, and changes in valence s population in the PbH4. PbH2 + H-2 reaction.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Optics
S. Breidenbach, E. Dizer, H. Cakir, Z. Harman
Summary: The study evaluates the shift of atomic energy levels due to hadronic vacuum polarization for hydrogenlike ions and muonic hydrogen. Energy corrections are calculated for low-lying levels using analytical wave functions, comparing the results to existing formulas from nonrelativistic theory.
Article
Physics, Multidisciplinary
T. Heinzl, A. Ilderton, B. King
Summary: The breakdown of QED perturbation theory has been observed in classical electrodynamics at lower field strengths than previously considered, suggesting the need for resummation in both classical and quantum scenarios. Detailed investigation has shown that unitarity removes diagrams previously believed to be responsible for the breakdown of QED perturbation theory, indicating a potential solution to this issue.
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
Jacek Zatorski, Vojtech Patkos, Krzysztof Pachucki
Summary: We perform a calculation of quantum electrodynamics effects in excited states with l > 1 of arbitrary twobody systems up to alpha 6 order. The results obtained are valid for hadronic atoms, as long as the strong interaction effects are negligible. We demonstrate that for circular states with l similar to n, the effective expansion parameter is Z alpha/n, which extends the applicability of the derived formulas to heavy ions. Moreover, inclusion of higherorder terms is feasible, which indicates that accurate measurements of excited states of, for example, muonic or antiprotonic hydrogenic ions can be used to determine the fundamental constants and to search for the existence of yet unknown long-range interactions.
Article
Optics
Lei Wu, Jun Jiang, Zhong-Wen Wu, Yong-Jun Cheng, Gediminas Gaigalas, Chen-Zhong Dong
Summary: This work presents an accurate determination of various parameters of Ar13+. The calculated wave functions, energy levels, and properties are in agreement with existing theoretical and experimental results.
Article
Chemistry, Physical
David Ferenc, Edit Matyus
Summary: A general computational scheme for the Bethe logarithm is developed, allowing routine evaluation of the leading-order QED correction for small polyatomic and polyelectronic molecular systems. The method relies on the Schwartz method and Hylleraas functional minimization. The implementation ensures positive definiteness of the functional for electronically excited states.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Astronomy & Astrophysics
Alejandro Miranda, Pablo Roig, Pablo Sanchez-Puertas
Summary: This paper revisits the contribution of axial-vector mesons to the hyperfine splitting of muonic hydrogen and finds significant differences compared to previous studies.
Article
Optics
Jin-Lu Wen, Jia-Dong Tang, Jun-Feng Dong, Xiao-Jiao Du, Shui-Ming Hu, Y. R. Sun
Summary: We propose a method to accurately measure the atomic beam using traveling-wave laser beams. The method is demonstrated by measuring the 2 3S - 2 3P transition in a slow helium atomic beam. The Doppler shift is effectively suppressed, reducing laser power dependence and eliminating modulation. Preliminary measurements indicate reduced uncertainty to sub-kHz level for the 2 3S - 2 3P transition of 4He.
Article
Chemistry, Physical
Artem. A. A. Kotov, Yury. S. S. Kozhedub, Dmitry. A. A. Glazov, Miroslav Ilias, Valeria Pershina, Vladimir. M. M. Shabaev
Summary: In this study, ab initio all-electron 4c- and 2c-relativistic coupled-cluster approaches were used to calculate the spectroscopic properties of CnO and FlO molecules, and a comparison with published data for HgO was conducted. The investigation focused on the dependence of the results on basis set parameters and approximations used, and the recommended values were found to have overall relative uncertainties of 1-2%. The calculated spectroscopic constants indicated a reactivity trend of HgO>FlO>CnO, which was confirmed by the trend in the adsorption energies, E-ads, on gold, quartz, and Teflon surfaces. The predicted low E-ads values for the latter case ensured the delivery of these molecules from the recoil chamber to the chemistry setup in gas-phase experiments.
Article
Physics, Multidisciplinary
Krzysztof Pachucki, Vladimir A. Yerokhin
Summary: This study examines how the transverse electromagnetic interaction between two pointlike particles is modified when one of the particles has a finite size. It is found that the traditional Breit approximation is not sufficient, and the interaction should be treated within the framework of Quantum Electrodynamics (QED). The complete QED formula for the finite-size nuclear recoil is derived, taking into account the coupling strength parameter Z alpha. Numerical calculations are performed for a range of Z values and validated against the oZ alpha thorn 5 contribution. Comparison with the Z alpha expansion reveals the significance of the oZ alpha thorn 6 term, which is linear in the nuclear radius and numerically dominates over the lower-order oZ alpha thorn 5 term.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
J. Sommerfeldt, V. A. Yerokhin, Th. Stoehlker, A. Surzhykov
Summary: We present calculations of Delbruck scattering with all-order Coulomb corrections for photon energies above the electron-positron pair creation threshold. Our method utilizes the Dirac-Coulomb Green's function and accounts for the interaction between the virtual electron-positron pair and the nucleus to all orders in the nuclear binding strength parameter αZ. Practical calculations are performed for 2.754 MeV photon scattering off plutonium atoms. Our results show that including the Coulomb corrections increases the scattering cross section by up to 50% in this case, resolving the long-standing discrepancy between experimental data and theoretical predictions.
PHYSICAL REVIEW LETTERS
(2023)
Article
Astronomy & Astrophysics
Krzysztof Pachucki, Vojtech Patkos, Vladimir A. Yerokhin
Summary: We present an accurate determination of the nuclear magnetic dipole moments of 6,7Li in atomic Li. The obtained results significantly improve upon the literature values and highlight the importance of reliable theoretical calculations of the nuclear shielding corrections.
Article
Chemistry, Physical
Anton Ryzhkov, Valeria Pershina, Miroslav Ilias, V. Shabaev
Summary: Adsorption energies (E-ads) of Lv-Og and Po-Rn on a gold surface were predicted using relativistic periodic density functional theory and SCM BAND software. The E-ads values of MH and MOH molecules on a gold surface were also calculated. The study aims to support gas-phase chromatography experiments on the reactivity/volatility of superheavy elements. The results show the adsorption strength follows the sequence: Hg > Fl > Og > Cn >> Rn, with E-ads values less than 100 kJ mol(-1).
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Physics, Nuclear
Yu. A. Demidov, M. G. Kozlov, A. E. Barzakh, V. A. Yerokhin
Summary: The magnetic hyperfine structure constants were calculated for low-lying levels in neutral potassium atoms, considering the effects of Bohr-Weisskopf (BW) and Breit-Rosenthal (BR). It was found that the 4p1/2 state of K I is not affected by both BR and BW corrections within the current theoretical uncertainties. By using this finding and the measured values of the A(4 p1/2) constants, the nuclear magnetic moments of several short-lived potassium isotopes were corrected. The BW correction was represented as a product of atomic and nuclear factors, and the atomic factor for the ground state of K I was calculated to extract nuclear factors for potassium I pi = 3/2+ isotopes from experimental data. Thus, the applicability of the single-particle nuclear model for calculating nuclear factors in these isotopes has been clarified.
Article
Optics
A. V. Malyshev, Y. S. Kozhedub, V. M. Shabaev
Summary: The bound-state QED approach is used to calculate the 2p3/2 -> 2s transition energies in He-, Li-, and Be-like uranium. Different perturbation theories are employed depending on the charge state of the uranium ion. The approach combines rigorous QED treatment with higher-order electron-correlation contributions evaluated within the Breit approximation. Several effects such as nuclear recoil, nuclear polarization, and nuclear deformation are also taken into account. The most accurate theoretical predictions, in good agreement with experimental data, are obtained.
Article
Optics
I. M. Savelyev, M. Y. Kaygorodov, Y. S. Kozhedub, A. V. Malyshev, I. I. Tupitsyn, M. Shabaev
Summary: Relativistic calculations are used to study the electronic structure of superheavy elements, taking into account the effects of relativistic, QED, and electron-electron correlation. The ground state configuration of these elements is being reexamined.
Article
Optics
V. A. Zaytsev, A. V. Malyshev, V. M. Shabaev
Summary: An ab initio method based on a complex-scaling approach for rigorous QED description of autoionizing states is developed. Nonperturbative treatment of autoionizing state binding energies in alpha Z, including all the many-electron QED contributions up to the second order, is achieved. Higher-order electron correlation, nuclear recoil, and nuclear polarization effects are also considered. The proposed formalism is applied to LL resonances in helium-like argon and uranium, resulting in the most accurate theoretical predictions for binding energies.
Article
Optics
Vladimir A. Yerokhin, Vojtech Patkos, Krzysztof Pachucki
Summary: We performed ab initio calculations of the QED effects for the 2 3S and 2 3P states of He-like ions at the order of m alpha 7. By combining the computed effects with previously calculated energies, the theoretical accuracy has been improved significantly. The obtained results for the transition energies agree well with experiment and previous calculations, while some inconsistency is observed for the ionization energies, possibly related to the theoretical-experimental discrepancy in helium ionization energies.
Article
Optics
A. V. Viatkina, V. A. Yerokhin, A. Surzhykov
Summary: In this study, many-body perturbation theory is used to calculate the isotope shifts of energy levels in Ca+ for even isotopes. The results show that the second-order mass shift and nuclear polarization correction are the dominant sources of King-plot nonlinearity for specific transitions.
Article
Optics
I. A. Maltsev, D. A. Tumakov, R. Popov, V. M. Shabaev
Summary: The relativistic energies and widths of hydrogenlike ions exposed to a uniform electric field are calculated and compared with nonrelativistic values. The role of relativistic effects is investigated using the complex-scaling technique in combination with a finite-basis method.
Article
Optics
I. S. Anisimova, A. V. Malyshev, D. A. Glazov, M. Y. Kaygorodov, Y. S. Kozhedub, G. Plunien, V. M. Shabaev
Summary: This paper presents a model-operator approach for fully relativistic calculations of the nuclear recoil effect on energy levels in many-electron atomic systems. The proposed method utilizes a one-electron model operator to handle the normal mass shift and can be easily incorporated into any relativistic calculation based on the Dirac-Coulomb-Breit Hamiltonian.
Article
Optics
Z. A. Mandrykina, V. A. Zaytsev, V. A. Yerokhin, V. M. Shabaev
Summary: The two-photon annihilation of a positron with an electron bound in the 1s state of a H-like ion is calculated within the fully relativistic QED framework. It is demonstrated that the two-photon annihilation channel dominates over the one-photon channel for the low- and medium-Z ions, whereas for the high-Z ions the situation reverses.
Article
Optics
M. E. Groshev, V. A. Zaytsev, V. A. Yerokhin, P-M Hillenbrand, Yu A. Litvinov, V. M. Shabaev
Summary: A fully relativistic approach is presented for calculating the bremsstrahlung emitted by an electron scattered off an ionic target. The influence of the target electrons on the emitted radiation properties is investigated and compared to experimental data.
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)
