Article
Chemistry, Multidisciplinary
Laetitia Farinacci, Lukas M. Veldman, Philip Willke, Sander Otte
Summary: Electron spin resonance (ESR) combined with scanning tunneling microscopy (ESR-STM) is used to investigate the electronic, magnetic, and chemical structure of individual spin centers on a surface. In this study, the hyperfine splitting of hydrogenated titanium atoms on MgO/Ag(001) is measured in a vector magnetic field, revealing strong anisotropy in both the g factor and the hyperfine tensor. By combining these results with symmetry properties obtained from STM images and a basic point charge model, the electronic ground state configuration of the titanium atom can be predicted.
Article
Chemistry, Physical
Xuping Shao, Run Chen, Yunxia Huang, Xiaohua Yang
Summary: The hyperfine structures of heterohalogen fluorides in their vibronic ground state are calculated and the Stark and Zeeman effects are studied. The heterohalogen fluorides exhibit simple hyperfine structure due to the 1/2 nuclear spin and 0 quadrupole of F atom. Our results provide essential information for further investigations and applications.
COMPUTATIONAL AND THEORETICAL CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Lasse K. Sorensen, Daniil E. Khrennikov, Valeriy S. Gerasimov, Alexander E. Ershov, Maxim A. Vysotin, Susanna Monti, Vadim Zakomirnyi, Sergey P. Polyutov, Hans Agren, Sergey Karpov
Summary: This study investigates the dependence of plasmon resonance excitations in ultrafine gold nanoparticles on heating and melting using an integrated approach. It reveals that the suppression of plasmon resonance is associated with an increase in atom mobility in the lattice and electron-phonon scattering.
Article
Chemistry, Multidisciplinary
Orion Ciftja
Summary: This paper investigates a finite system of classical electric dipoles localized at the sites of a regular one-dimensional crystal lattice and calculates the ground state energy for any number of dipoles. The expression for the ground state energy is given in terms of special functions and converges to the correct result in the limit of infinitely many dipoles. Additionally, simpler but accurate approximate expressions for the ground state energy are introduced.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2023)
Article
Optics
Ziqiang Tian, Zhiming Tang, Yi Li, Yang Yang, Zhongwen Wu, Yaming Zou
Summary: This study investigates the linear polarization of magnetic-quadrupole emission lines of Be-like ions with nuclear spin through the use of density-matrix theory and relativistic distorted-wave theory. The effects of hyperfine interaction and different nuclear magnetic dipole moments on the polarization of these lines are explored. The findings suggest that precise polarization measurements of magnetic-quadrupole lines could be used to study the hyperfine interaction and nuclear magnetic dipole moment of isotopes with nonzero spins.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2023)
Article
Physics, Applied
Gabriele Barrera, Paolo Allia, Paola Tiberto
Summary: This study investigates the magnetic and thermal properties of clustered magnetite nanoparticles in a high-frequency magnetic field using rate equations. It finds that particle clustering significantly modifies the shape of hysteresis loops and affects the power released as heat to a host medium. Clustering of particles can either enhance or reduce the released power, with opposite effects observed depending on the dimensions of the clusters.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Physics, Multidisciplinary
Gianfranco Spavieri, George T. Gillies, Miguel Rodriguez, Maribel Perez
Summary: Classical electrodynamics predicts that the interaction force between a moving charge and a magnetic dipole is affected by the time-varying total momentum of the interaction fields. The equations of motion for particles are derived from the total stress-energy tensor, assuming the validity of Maxwell's equations and the conservation of total momentum. Applications to the Aharonov-Bohm effects suggest that the observed phase shift may be attributed to the relative lag between interfering particles caused by the effective local force.
CHINESE PHYSICS LETTERS
(2021)
Article
Physics, Multidisciplinary
Chen Run, Shao Xu-Ping, Huang Yun-Xia, Yang Xiao-Hua
Summary: The transition dipole and selection rules of the hyperfine-rotation spectrum for J = 1 <- 0 in the BrF molecule's vibronic ground state are derived. The spectral lines are a result of both electric and nuclear magnetic dipole transitions, with the latter making a minimal contribution to the intensity. The spectral linewidth is determined to be approximately 18 kHz, and the positions of the spectral lines are accurately simulated through diagonalization of the Hamiltonian matrix. Additionally, the nuclear spin-spin interaction affects both the spectral positions and the sequence of the spectra. Quantum chemical calculations can provide precise molecular constants for spectral assignments.
ACTA PHYSICA SINICA
(2023)
Correction
Optics
K. Miao, J. W. Zhang, X. L. Sun, S. G. Wang, A. M. Zhang, K. Liang, L. J. Wang
Summary: An erratum was published to correct an error in the calculation of the ground-state hyperfine splitting frequency of the Cd-113(+) ion, resulting in a revised value of 15199862855.0287(10) Hz.
Article
Chemistry, Physical
Cyril Falvo, Hebin Li
Summary: In this article, the simulation study of the linear and nonlinear spectroscopy of dense atomic vapors is presented. It is shown that temperature has an important impact on the self-broadening mechanisms of the linear and nonlinear spectra by including thermal velocity explicitly. The response functions in the short time limit are provided using the two-body approximation, revealing that double quantum spectroscopy directly probes the transition amplitude of the electronic excitation between two atoms in atomic vapors. An expression for the double quantum spectrum that includes the effect of Doppler broadening is proposed, and the effect of density on the spectrum is discussed. It is demonstrated that the double quantum spectrum scales with the atomic density when Doppler broadening is negligible compared to self-broadening, while it scales as the square of the density when Doppler broadening dominates.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
AlAhmadi N. Ameenah
Summary: The study demonstrates that the nanocrystal system coupled via dipolar interaction shows an anti-crossing behavior under an external applied magnetic field, resulting in a Lorentz-shaped photoluminance intensity signal with an unusual dip-shape at the zero detuned states. This dip-shape corresponds to the point where crossing would occur in the absence of dipolar interaction.
RESULTS IN PHYSICS
(2021)
Article
Optics
R. P. de Groote, S. Kujanpaa, A. Koszorus, J. G. Li, I. D. Moore
Summary: The hyperfine constants of a specific state in neutral Yb were measured using three different dipole transitions, showing no evidence of a nonzero octupole moment in Yb-173.
Article
Physics, Multidisciplinary
Muhammad Kaleem, Zaheer Uddin, Yixin Xu, Zhenwen Dai
Summary: In this study, the hyperfine structure constants of Scandium were analyzed using Fourier Transform Spectra. The hf constants of 104 even levels and 95 odd levels were determined and compared with published data, showing a good agreement in most cases. Additionally, hf constants for 8 odd and 10 even levels were determined for the first time from experimental data, and modifications were made to seven HFS constants.
Article
Spectroscopy
Nupur Pandey, Neeraj Tewari, Sanjay Pant, Mohan Singh Mehata
Summary: The study investigated the spectral behavior of 6AQ in different solvents, showing solvatochromism with increasing Stokes shift and a more polar excited state possibly due to a change in geometry and involvement of pi -> pi* transition. The dipole moments of the ground state and excited state were determined, with the excited state having a higher dipole moment possibly due to intramolecular charge transfer. The molecule exhibited reasonable band-gap energy and good blue CIE coordinates, suggesting potential applications in optoelectronics.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Physics, Multidisciplinary
E. M. Smith, O. Benton, D. R. Yahne, B. Placke, R. Schaefer, J. Gaudet, J. Dudemaine, A. Fitterman, J. Beare, A. R. Wildes, S. Bhattacharya, T. DeLazzer, C. R. C. Buhariwalla, N. P. Butch, R. Movshovich, J. D. Garrett, C. A. Marjerrison, J. P. Clancy, E. Kermarrec, G. M. Luke, A. D. Bianchi, K. A. Ross, B. D. Gaulin
Summary: The magnetic properties of Ce2Zr2O7, which has dipole-octupole character, were studied using polarized neutron diffraction and heat capacity measurements. The results suggest that Ce2Zr2O7 exhibits the characteristics of a U(1)(pi) quantum spin liquid state, with a possible boundary between dipolar and octupolar character.
Article
Optics
J. M. Sampaio, J. Ekman, B. P. E. Tee, R. du Rietz, B. Q. Lee, M. S. Pires, P. Jonsson, T. Kibedi, M. Vos, A. E. Stuchbery, J. P. Marques
Summary: New 125 I atomic decay emission data are presented in this study, which are calculated based on the multi-configuration Dirac-Hartree-Fock method. The comparison with the experimental electron emission spectrum shows that the new calculations can reproduce the structure of the Auger electron peaks.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2022)
Article
Computer Science, Interdisciplinary Applications
Yan Ting Li, Kai Wang, Ran Si, Michel Godefroid, Gediminas Gaigalas, Chong Yang Chen, Per Jonsson
Summary: This study demonstrates a computational method based on configuration state function generators (CSFGs) that significantly reduces the computational load in relativistic calculations and further reduces the CPU time by limiting the Breit integrals.
COMPUTER PHYSICS COMMUNICATIONS
(2023)
Article
Optics
B. Atalay, P. Jonsson, T. Brage
Summary: Multiconfiguration Dirac-Hartree-Fock (MCDHF) and relativistic configuration interaction (RCI) calculations were performed for 22 states in singly ionized tin (Sn II), taking into account valence-valence and core-valence correlation effects. The results provide complete and consistent data sets for level energies, wavelengths, oscillator strengths, lifetimes, and transition rates. Comparison with existing theoretical and experimental results shows excellent agreement for calculated excitation energies and good agreement for lifetimes and transition rates.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2023)
Article
Physics, Atomic, Molecular & Chemical
Yanting Li, Per Jonsson, Michel Godefroid, Gediminas Gaigalas, Jacek Bieron, Jose Pires Marques, Paul Indelicato, Chongyang Chen
Summary: There is a strong coupling between the localization of the orbital set and the configuration state function (CSF) expansion in multiconfiguration Dirac-Hartree-Fock (MCDHF) calculations. The inadequacy of a single orbital set for determining correlated effects important for computed properties can lead to irregular or oscillating convergence patterns. To address this problem, a procedure of merging separately optimized, non-orthogonal orbital sets is proposed. This procedure improves convergence patterns and efficiently captures correlation effects.
Article
Physics, Atomic, Molecular & Chemical
Per Jonsson, Michel Godefroid, Gediminas Gaigalas, Joergen Ekman, Jon Grumer, Wenxian Li, Jiguang Li, Tomas Brage, Ian P. Grant, Jacek Bieron, Charlotte Froese Fischer
Summary: Computational atomic physics is essential for advancing fundamental physics knowledge and interpreting data from various large-scale research facilities. This article reviews the relativistic multiconfiguration method as applied to the General Relativistic Atomic Structure Package and provides examples of calculations relevant to nuclear physics and astrophysics.
Article
Physics, Atomic, Molecular & Chemical
Yanting Li, Jinqing Li, Changxian Song, Chunyu Zhang, Ran Si, Kai Wang, Michel Godefroid, Gediminas Gaigalas, Per Jonsson, Chongyang Chen
Summary: The latest version of GRASP2018 has suboptimal subroutines/algorithms due to the computer limitations in the 1980s. This study presents a modification on the relativistic self-consistent-field procedure and configuration-interaction calculations, significantly improving their efficiency. The modified GRASP version reduces CPU times by several tens or more. MPI performances of all codes are analyzed, showing good scaling except for diagonalization.
Article
Astronomy & Astrophysics
M. C. Li, W. Li, P. Jonsson, A. M. Amarsi, J. Grumer
Summary: Accurate and extensive atomic data for neutral nitrogen are provided, including energy levels, lifetimes, and transition probabilities. The calculations are based on advanced relativistic methods and show excellent agreement with experimental data. The uncertainties of the computed transition data are estimated using statistical analysis.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Physics, Atomic, Molecular & Chemical
Per Jonsson, Gediminas Gaigalas, Charlotte Froese Fischer, Jacek Bieron, Ian P. Grant, Tomas Brage, Jorgen Ekman, Michel Godefroid, Jon Grumer, Jiguang Li, Wenxian Li
Summary: grasp is a Fortran 95 software package for parallel computing under MPI, specifically designed for atomic physics research. It enables computation of any observed atomic property based on a given wave function. The accuracy of the wave function is challenged differently by different properties. This software is distributed under the MIT Licence.
Article
Physics, Atomic, Molecular & Chemical
Yanting Li, Gediminas Gaigalas, Wenxian Li, Chongyang Chen, Per Jonsson
Summary: Fine-tuning of the Hamiltonian matrix improves the accuracy of calculated energy separations by adjusting the diagonal elements to match experimental results. In calculations based on jj-coupled configuration state functions, the diagonally dominant requirement is often not met. An alternative method that transforms the matrix to LSJ-coupling and then back to jj-coupling is presented to overcome this problem. Implementation of this method in the General Relativistic Atomic Structure Package leads to improved convergence and results in the computation of transitions in C III and Rydberg transitions in B I.
Editorial Material
Physics, Atomic, Molecular & Chemical
Jacek Bieron, Charlotte Froese Fischer, Per Jonsson
Article
Optics
Chun Yu Zhang, Jin Qing Li, Kai Wang, Ran Si, Michel Godefroid, Per Jonsson, Jun Xiao, Ming Feng Gu, Chong Yang Chen
Summary: The atomic properties of n = 3 levels for W47+ - W55+ ions (Z = 74) are systematically calculated using two different methods. The calculated wavelengths and transition rates for electric-and magnetic-dipole transitions are found to be accurate and can be used for future experiments and theoretical calculations.
