Article
Materials Science, Multidisciplinary
P. Hollebon, T. Sjostrom
Summary: Density functional theory has greatly advanced our understanding of dense, strongly coupled systems in the condensed-matter regime. The computational cost of accurately describing a thermal ensemble of electrons at high temperatures has been a major obstacle in practical Kohn-Sham calculations. In this work, the Thomas-Fermi density of states, equivalent to a local plane-wave approximation, is shown to yield improved results for thermodynamic quantities, electron density profiles, and interatomic forces with fewer required states.
Article
Astronomy & Astrophysics
Zu-Xing Yang, Xiao-Hua Fan, Zhi-Pan Li, Haozhao Liang
Summary: In this study, a Kohn-Sham scheme based multi-task neural network is developed for supervised learning of nuclear shell evolution. The training set consists of single-particle wave functions and occupation probabilities of 320 nuclei obtained from Skyrme density functional theory. The deduced density distributions, momentum distributions, and charge radii show good agreements with benchmarking results for untrained nuclei. Shell evolution and charge-radius-based calibration further improve the network's predictive capability, opening up possibilities for inferring correlations among observables in nuclear complex systems.
Article
Chemistry, Physical
Rodrigo A. Mendes, Roberto L. A. Haiduke, Rodney J. Bartlett
Summary: Exchange-correlation functionals from Density Functional Theory developed under Correlated Orbital Theory address the prominent errors in Kohn-Sham DFT, particularly focusing on charge transfer and Rydberg excitation energies. The Quantum Theory Project XC functionals offer improvements for electronic excitations, with QTP family showing good results for charge-transfer and Rydberg states. However, there is room for enhancement in valence state excitation energies.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Computer Science, Interdisciplinary Applications
M. A. Yalcin, I Temizer
Summary: A numerical framework is developed for aspherical atomic Kohn-Sham density functional theory calculations, utilizing higher-order finite elements as radial discretization and a multipole expansion for controlling spherical resolution. The approach successfully addresses both all-electron and nonlocal pseudopotential calculations and demonstrates systematic convergence and high accuracy in the presence of strong aspherical external fields. In summary, this framework offers an adaptive local enrichment route for electronic structure calculations in the finite element method context.
COMPUTER PHYSICS COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Chih-Chuen Lin, Phani Motamarri, Vikram Gavini
Summary: The tensor-structured algorithm proposed in this study utilizes a Tucker tensor basis adapted to the Kohn-Sham Hamiltonian for efficient large-scale density functional theory (DFT) calculations with exponential convergence in the ground-state energy. Demonstrating sub-quadratic scaling with system-size, the algorithm outperforms plane-wave DFT implementation for systems beyond 2000 electrons.
NPJ COMPUTATIONAL MATERIALS
(2021)
Article
Computer Science, Interdisciplinary Applications
Leonardo Zepeda-Nunez, Yixiao Chen, Jiefu Zhang, Weile Jia, Linfeng Zhang, Lin Lin
Summary: This paper introduces the Deep Potential method and demonstrates how its network structure can effectively represent the mapping from atomic configurations to electron densities in Kohn-Sham density function theory. The adapted network architecture, called Deep Density, effectively represents the self-consistent electron density as a linear combination of contributions from many local clusters, while satisfying specific symmetries and being transferable to different system sizes. The Deep Density achieves excellent performance with relatively few training snapshots in various types of systems, from one-dimensional to three-dimensional, including small organic molecules and extended systems like water and aluminum.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Computer Science, Interdisciplinary Applications
Nathan Vaughn, Vikram Gavini, Robert Krasny
Summary: TAGI is a real-space computational method for all-electron Kohn-Sham Density Functional Theory that uses specialized Green Iteration and treecode acceleration to speed up convergence, with various techniques to improve efficiency and accuracy in energy calculations for atoms and small molecules.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Chemistry, Physical
Bhupalee Kalita, Ryan Pederson, Jielun Chen, Li Li, Kieron Burke
Summary: The study tests the application of KSR in weakly correlated systems and introduces spin-adapted KSR with trainable local, semilocal, and nonlocal approximations. The results show that the generalization error of the semilocal approximation is comparable to other methods, while the nonlocal functional outperforms any existing machine learning functionals in predicting the ground-state energies of test systems.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Engineering, Multidisciplinary
K. Karaca, I. Temizer
Summary: Hellmann-Feynman forces are derived using the numerical framework of the finite element method, and their variational consistency is examined in all-electron and pseudopotential settings. The study demonstrates the systematic convergence of the finite element framework for energy, force, geometric configuration, and molecular statics parameters in nonperiodic systems. These findings contribute to recent advances in the application of the finite element method for ab initio molecular dynamics.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Editorial Material
Mathematics, Applied
Guanghui Hu, Ting Wang, Jie Zhou
Summary: Dai et al. proposed a gradient flow model and a numerical scheme for ground state calculations in Kohn-Sham density functional theory. Their method can automatically preserve the orthonormality of wave functions, making it attractive for simulations of large scale systems. They introduced two extensions to improve the efficiency of the method: linearization of the original nonlinear scheme and the introduction of adaptivity in the algorithm. Numerical experiments successfully demonstrated the effectiveness of their method.
EAST ASIAN JOURNAL ON APPLIED MATHEMATICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Shizhe Jiao, Zhenlin Zhang, Kai Wu, Lingyun Wan, Huanhuan Ma, Jielan Li, Sheng Chen, Xinming Qin, Jie Liu, Zijing Ding, Jinlong Yang, Yingzhou Li, Wei Hu, Lin Lin, Chao Yang
Summary: KSSOLV is a MATLAB toolbox for performing Kohn-Sham density functional theory (DFT) calculations with a plane-wave basis set. It is used to study the electronic structures of molecules and solids, and includes new functionalities and algorithms for improved performance.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Engineering, Multidisciplinary
I. Temizer
Summary: Kohn-Sham density functional theory, coupled with higher-order finite element methods, is utilized to investigate the application of nonlocal pseudopotentials with nonlinear core corrections. The study develops a suitable weak formulation for the nonlinear eigenvalue problem and discretizes it using traditional Lagrange elements and isogeometric analysis based on B-splines. Numerical investigations on single atoms and larger molecules confirm the computational framework's ability to meet stringent accuracy requirements and converge at optimal rates.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Computer Science, Interdisciplinary Applications
Chih-Chuen Lin, Vikram Gavini
Summary: The TTDFT code utilizes a tensor-structured algorithm with GPU acceleration for ground-state DFT calculations, solving the discrete Kohn-Sham problem with a localized Tucker tensor basis and Chebyshev filtered subspace iteration method. The computational performance is demonstrated on benchmark studies of aluminum nanoparticles and silicon quantum dots, achieving up to 8-fold GPU-CPU speedup.
COMPUTER PHYSICS COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Bikash Kanungo, Jeffrey Hatch, Paul M. Zimmerman, Vikram Gavini
Summary: The conventional approaches to the inverse density functional theory problem assume nondegeneracy of the Kohn-Sham eigenvalues, limiting their use in open-shell systems. This study presents a generalized approach that allows for degenerate KS eigenvalues and fractional occupancy of the orbitals, enabling the handling of noninteracting ensemble-v-representable densities. Comparison of exact and model exchange-correlation potentials shows substantial relative errors in the model potentials.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Mathematics, Applied
Soeren Behr, Benedikt R. Graswald
Summary: The dissociation limit for molecules of the type X-2 in the Kohn-Sham density functional theory setting was studied, and numerical results verified that the energy of the H-2 molecule is twice that of an H atom.
NONLINEAR ANALYSIS-THEORY METHODS & APPLICATIONS
(2022)
Article
Physics, Multidisciplinary
V Manea, J. Karthein, D. Atanasov, M. Bender, K. Blaum, T. E. Cocolios, S. Eliseev, A. Herlert, J. D. Holt, W. J. Huang, Yu A. Litvinov, D. Lunney, J. Menendez, M. Mougeot, D. Neidherr, L. Schweikhard, A. Schwenk, J. Simonis, A. Welker, F. Wienholtz, K. Zuber
PHYSICAL REVIEW LETTERS
(2020)
Review
Physics, Nuclear
Michael Bender, Remi Bernard, George Bertsch, Satoshi Chiba, Jacek Dobaczewski, Noel Dubray, Samuel A. Giuliani, Kouichi Hagino, Denis Lacroix, Zhipan Li, Piotr Magierski, Joachim Maruhn, Witold Nazarewicz, Junchen Pei, Sophie Peru, Nathalie Pillet, Jorgen Randrup, David Regnier, Paul-Gerhard Reinhard, Luis M. Robledo, Wouter Ryssens, Jhilam Sadhukhan, Guillaume Scamps, Nicolas Schunck, Cedric Simenel, Janusz Skalski, Ionel Stetcu, Paul Stevenson, Sait Umar, Marc Verriere, Dario Vretenar, Michal Warda, Sven Aberg
JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS
(2020)
Article
Physics, Nuclear
J. Dobaczewski, P. Baczyk, P. Becker, M. Bender, K. Bennaceur, J. Bonnard, Y. Gao, A. Idini, M. Konieczka, M. Kortelainen, L. Prochniak, A. M. Romero, W. Satula, Y. Shi, T. R. Werner, L. F. Yu
Summary: The new version of the HFODD code includes a variety of new features such as zero-range and finite-range terms, as well as corrections for several errors in previous versions.
JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS
(2021)
Article
Physics, Nuclear
Guillaume Scamps, Stephane Goriely, Erik Olsen, Michael Bender, Wouter Ryssens
Summary: A new mass model based on Skyrme-EDF was developed, using a three-dimensional coordinate-space representation to consider both axial and triaxial deformations during adjustment. To handle the increase in computational cost, a committee of multilayer neural networks was employed to guide towards the overall best fit in parameter space. The resulting BSkG1 mass model achieved good agreement with known masses and charge radii.
EUROPEAN PHYSICAL JOURNAL A
(2021)
Article
Physics, Multidisciplinary
Benjamin Bally, Michael Bender, Giuliano Giacalone, Vittorio Soma
Summary: This study utilizes data from high-energy collision experiments to demonstrate the evidence of nonaxiality in the ground state of 129Xe ions, indicating the presence of triaxial deformation in the low-energy structure. This finding showcases the unique capabilities of precision collider machines in imaging the collective structure of atomic nuclei.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Nuclear
M. Hukkanen, W. Ryssens, P. Ascher, M. Bender, T. Eronen, S. Grevy, A. Kankainen, M. Stryjczyk, L. Al Ayoubi, S. Ayet, O. Beliuskina, C. Delafosse, W. Gins, M. Gerbaux, A. Husson, A. Jokinen, D. A. Nesterenko, I. Pohjalainen, M. Reponen, S. Rinta-Antila, A. De Roubin, A. P. Weaver
Summary: Precision mass measurements of neutron-rich rhodium isotopes have been conducted at the JYFLTRAP Penning trap mass spectrometer at the IGISOL facility. The study reports on the masses of ground and isomeric states in Rh-110, Rh-112, Rh-114, Rh-116, Rh-118, and Rh-120. The phase-imaging ion-cyclotron-resonance (PI-ICR) technique was used to separate and measure the isomeric states for the first time.
Article
Physics, Nuclear
Wouter Ryssens, Guillaume Scamps, Stephane Goriely, Michael Bender
Summary: Large-scale models of nuclear structure are essential for providing consistent datasets for nucleosynthesis simulations. In the recent study, the BSkG2 model based on an energy density functional was introduced, which considers triaxial deformation and time-reversal symmetry breaking. The BSkG2 model achieves a state-of-the-art global description of nuclear ground state properties and demonstrates unprecedented accuracy in reproducing fission properties and known masses. The model's ability to accurately calculate fission barriers of actinide nuclei, including odd-mass and odd-odd systems, highlights its importance for large-scale studies of nuclear structure.
EUROPEAN PHYSICAL JOURNAL A
(2023)
Article
Physics, Nuclear
B. Bally, G. Giacalone, M. Bender
Summary: In this article, the structure of Au-197 is studied using multi-reference energy density functional calculations. The results show good agreement with experimental data and provide information about the average deformation and intrinsic shape of the nucleus.
EUROPEAN PHYSICAL JOURNAL A
(2023)
Article
Physics, Nuclear
Wouter Ryssens, Guillaume Scamps, Stephane Goriely, Michael Bender
Summary: Models based on nuclear energy density functionals provide access to various observables for nuclei, and lifting the time-reversal invariance assumption allows us to study ground state properties of odd-mass and odd-odd nuclei. By adjusting parameters and incorporating fission barrier information, the resulting model shows high accuracy in known nuclear masses, charge radii, and fission isomer excitation energies.
EUROPEAN PHYSICAL JOURNAL A
(2022)
Article
Physics, Nuclear
Benjamin Bally, Giuliano Giacalone, Michael Bender
Summary: This study reports on state-of-the-art calculations of the triaxial structure of Xe-128, Xe-129, and Xe-130 isotopes using advanced computational methods. The research shows that all three isotopes have a prominent triaxial ground state, and the calculations reproduce the experimental results fairly well.
EUROPEAN PHYSICAL JOURNAL A
(2022)
Article
Physics, Nuclear
Wouter Ryssens, Michael Bender
Summary: Efforts to improve the spectroscopic quality of nuclear energy density functionals of the Skyrme type are ongoing, with recent exploration of higher-order gradient terms. While advancements have been made in extending the traditional form of EDFs, further work is needed to better discriminate between NLO and N2LO terms and exploit the additional degrees of freedom offered by the latter.
Article
Physics, Nuclear
Benjamin Bally, Michael Bender
Summary: This work provides a general introduction to the projection method for restoring broken symmetries in many-body systems, investigates the numerical implementation and practical aspects of particle-number and angular-momentum projection, and analyzes the implications of intrinsic symmetries of the symmetry-breaking states when projecting them. The results include a concise presentation of the method, achieving high accuracy in numerical evaluations, and reducing computational costs by leveraging symmetries of reference states. The quantum-number projection technique is versatile, efficient, and can be applied to various nuclear systems to restore their symmetry.
Article
Physics, Nuclear
R. Briselet, Ch Theisen, B. Sulignano, M. Airiau, K. Auranen, D. M. Cox, F. Dechery, A. Drouart, Z. Favier, B. Gall, T. Goigoux, T. Grahn, P. T. Greenlees, K. Hauschild, A. Herzan, R-D Herzberg, U. Jakobsson, R. Julin, S. Juutinen, J. Konki, M. Leino, A. Lopez-Martens, A. Mistry, P. Nieminen, J. Pakarinen, P. Papadakis, P. Peura, E. Rey-Herme, P. Rahkila, J. Rubert, P. Ruotsalainen, M. Sandzelius, J. Saren, C. Scholey, J. Sorri, S. Stolze, J. Uusitalo, M. Vandebrouck, A. Ward, M. Zielinska, B. Bally, M. Bender, W. Ryssens
Article
Physics, Nuclear
E. Verstraelen, A. Teigelhoefer, W. Ryssens, F. Ames, A. Barzakh, M. Bender, R. Ferrer, S. Goriely, P-H Heenen, M. Huyse, P. Kunz, J. Lassen, V Manea, S. Raeder, P. Van Duppen
Article
Physics, Nuclear
W. Ryssens, M. Bender, K. Bennaceur, P-H Heenen, J. Meyer
