Article
Chemistry, Physical
Jiawei Zhan, Marco Govoni, Giulia Galli
Summary: Electronic structure calculations based on DFT have successfully predicted ground-state properties of molecules and materials. However, the currently used exchange and correlation functionals are often inaccurate for describing the electronic properties of heterogeneous solids. Here, we present a dielectric-dependent range-separated hybrid functional, SE-RSH, which accurately predicts the electronic structure of various nonmetallic interfaces, solids, and nanoparticles.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Wenna Ai, Wei-Hai Fang, Neil Qiang Su
Summary: This study focuses on the range-separated correlation in long-range corrected hybrid functionals, presenting a theory on its derivation and proving its reliability and effectiveness. The new functional proposed in this work outperforms the traditional LC-BLYP method in various tests and maintains important properties of the XC potential.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Chemistry, Physical
Karno Schwinn, Felipe Zapata, Antoine Levitt, Eric Cances, Eleonora Luppi, Julien Toulouse
Summary: This article explores the merits of linear-response range-separated time-dependent density-functional theory (TDDFT) for calculating photoionization spectra. Two variants of range-separated TDDFT are considered and compared with standard methods. The article demonstrates the calculation of photoionization spectra using the Sternheimer approach and applies it to the photoionization spectrum of the Be atom. The results show significant improvement over traditional methods.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Katarzyna Pernal, Michal Hapka
Summary: Range-separated multiconfigurational density functional theory (RS MC-DFT) combines density functional and wavefunction theories by partitioning the electron interaction operator and modeling with different methods. RS MC-DFT aims to increase versatility and accuracy of methods while reducing computational cost. Variants of RS MC-DFT can be divided into single-determinant-based and multideterminantal approaches for describing electron correlation energy. Applications include ground-state properties of molecules and noncovalent interactions, as well as time-dependent linear-response theory and direct approaches to excited states. Advantages of RS MC-DFT over conventional DFT and ab initio methods are assessed for each area of application.
WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Subrata Jana, Arghya Ghosh, Lucian A. Constantin, Prasanjit Samal
Summary: A simple and effective screening parameter is constructed for the screened range-separated exchange-correlation hybrid functional based on the compressibility sum rule in the context of linear-response time-dependent density functional theory. When applied to the dielectric-dependent hybrid (DDH), it shows remarkable accuracy for bulk solids compared to parameters obtained from fitting with the model dielectric function or depending on the valence electron density of materials. The screening parameter developed in this study is simple, realistic, and physically appealing, and can be easily obtained using the average of the local Seitz radius over the unit-cell volume of the bulk solid. Furthermore, the constructed DDH demonstrates very good accuracy in energy band gaps, occupied d band positions, ionization potentials, optical properties of semiconductors and insulators, and geometries of bulk solids (equilibrium lattice constants and bulk moduli).
Article
Chemistry, Physical
Susanne Furst, Martin Kaupp
Summary: The recently reported ?LH22t range-separated local hybrid functional can provide results for ionization energies, electron affinities, and fundamental gaps that are comparable to OT-RSH methods, approaching the quality of GW results, without the need for system-specific tuning. This functional also gives excellent outer-valence quasiparticle spectra and is accurate for various excitation types, making it a promising new tool in molecular electronics.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
David Mester, Mihaly Kallay
Summary: The spin-scaling techniques in the RS-DH method have shown robustness and reduced computational expenses, improving the functional methods and having a broad application scope.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
David Mester, Mihaly Kallay
Summary: A simple and robust range-separated double-hybrid time-dependent density functional approach is proposed for accurate calculation of excitation energies. The new approach shows improvement over standard double hybrids and provides a more robust and accurate alternative in most cases, surpassing existing range-separated hybrid and double-hybrid functionals on average.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2021)
Article
Chemistry, Physical
Susanne Fuerst, Matthias Haasler, Robin Grotjahn, Martin Kaupp
Summary: We successfully implemented range-separated local hybrid functionals (RSLHs) into the TURBOMOLE program package for the first time, allowing for the computation of ground-state energies, nuclear gradients, and excitation energies. The computational effort of RSLHs is comparable to regular local hybrid functionals (LHs), with a 2-3 times increase in overall timings. The advanced RSLH, omega LH22t, performs well for a wide range of evaluations.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Susanne Fuerst, Matthias Haasler, Robin Grotjahn, Martin Kaupp
Summary: We present the implementation of range-separated local hybrid functionals (RSLHs) in TURBOMOLE, allowing for efficient calculation of ground-state and excitation energies. Compared to regular local hybrid functionals (LHs), RSLHs have similar scaling with system or basis set size and increase total timings by a factor of 2-3. A specific RSLH, omega LH22t, is optimized for atomization energies and reaction barriers, showing superior performance for a wide range of ground-state and excited-state quantities. It approaches the accuracy of the best local hybrids to date for various excitation energies and performs remarkably for charge-transfer excitations.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Multidisciplinary Sciences
Dahvyd Wing, Guy Ohad, Jonah B. Haber, Marina R. Filip, Stephen E. Gant, Jeffrey B. Neaton, Leeor Kronik
Summary: This study presents a simple and inexpensive method to accurately predict fundamental band gaps of crystalline solid-state systems. The method, based on nonempirical optimal tuning of a screened range-separated hybrid functional, has been benchmarked against experiment and found to yield quantitative accuracy across a range of systems.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Multidisciplinary Sciences
Rachel Garrick, Leeor Kronik, Tim Gould
Summary: A generalized adiabatic connection for any type of range-separated hybrid functional employed within generalized Kohn-Sham theory is presented, which allows for a rigorous distinction between multiplicative exchange and correlation components. The connection is defined in terms of both generalized and conventional KS orbitals, although using only the KS orbitals introduces a small error in practical calculations. The new adiabatic connection is expected to assist in the development and assessment of RSH functionals.
ADVANCED THEORY AND SIMULATIONS
(2022)
Article
Physics, Multidisciplinary
Vivekanand Shukla, Yang Jiao, Jung-Hoon Lee, Elsebeth Schroeder, Jeffrey B. Neaton, Per Hyldgaard
Summary: We introduce a new general-purpose van der Waals density functional, vdW-DF2-ahbr, which combines vdW-DF2 correlation with a screened Fock exchange. It successfully resolves spurious exchange binding and density-driven errors, significantly improving the performance of existing vdW-DFs for molecular problems.
Article
Materials Science, Multidisciplinary
Rita Maji, Elena Degoli, Monica Calatayud, Valerie Veniard, Eleonora Luppi
Summary: Currently, the most accurate method to describe excitons in solids is GW-BSE, but the computation cost has led to the alternative use of TDDFT. Long-range corrected exchange-correlation kernels and range-separated hybrid functionals are the most efficient strategies to describe optical spectra in TDDFT. This study compares their performance for describing excitons in solids and provides new perspectives for theoretical developments of these functionals.
Article
Chemistry, Physical
Marvin Friede, Sebastian Ehlert, Stefan Grimme, Jan-Michael Mewes
Summary: This study investigates the interdependency between dispersion correction parameters and the range-separation parameter omega in large molecules. The results show that some functionals are strongly affected by omega values, leading to overbinding and poor performance. Strategies to mitigate these issues are discussed, providing insights for future improvements.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
Szymon Smiga, Ireneusz Grabowski, Mateusz Witkowski, Bastien Mussard, Julien Toulouse
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2020)
Article
Chemistry, Physical
Pierre-Francois Loos, Barthelemy Pradines, Anthony Scemama, Emmanuel Giner, Julien Toulouse
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2020)
Article
Chemistry, Physical
Emmanuel Giner, Anthony Scemama, Pierre-Francois Loos, Julien Toulouse
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Julien Paquier, Emmanuel Giner, Julien Toulouse
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Yuan Yao, Emmanuel Giner, Junhao Li, Julien Toulouse, C. J. Umrigar
JOURNAL OF CHEMICAL PHYSICS
(2020)
Article
Chemistry, Physical
Julien Paquier, Julien Toulouse
Summary: In this study, a complementary short-range correlation relativistic local-density-approximation functional was constructed for use in relativistic range-separated density-functional theory. By performing relativistic random-phase-approximation calculations of the correlation energy of the relativistic homogeneous electron gas, the behavior at high densities was studied and the results were fitted to a parametrized expression. The obtained functional is expected to be useful for electronic-structure calculations of strongly correlated systems containing heavy elements.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2021)
Article
Chemistry, Physical
Emmanuel Giner, Diata Traore, Barthelemy Pradines, Julien Toulouse
Summary: This work presents a self-consistent extension of a density-based basis-set correction method for wave function electronic-structure calculations. The study shows that the self-consistent approach allows for lowering total energy and changing wave functions under the effect of basis-set correction, leading to improved dipole moments. The research confirms the validity of the density-based basis-set correction scheme.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Diata Traore, Emmanuel Giner, Julien Toulouse
Summary: This article re-examines the basis-set correction theory based on density-functional theory and proposes an improved variant of basis-set correction. It also demonstrates how to develop a local-density approximation using the basis-set correction method.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Yuan Yao, Emmanuel Giner, Tyler A. Anderson, Julien Toulouse, C. J. Umrigar
Summary: The semistochastic heat-bath configuration interaction method provides near-full configuration interaction accuracy but faces difficulties in basis size convergence. A basis-set correction method based on range-separated density functional theory has been shown to significantly speed up basis-set convergence in SHCI calculations.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Diata Traore, Julien Toulouse, Emmanuel Giner
Summary: This study proposes an approach to accelerate the computation of molecular properties in wave-function theory by using a basis-set correction based on density-functional theory. Numerical tests on dipole moments in coupled-cluster with single, double, and perturbative triple excitations show a clear improvement in basis convergence.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Karno Schwinn, Felipe Zapata, Antoine Levitt, Eric Cances, Eleonora Luppi, Julien Toulouse
Summary: This article explores the merits of linear-response range-separated time-dependent density-functional theory (TDDFT) for calculating photoionization spectra. Two variants of range-separated TDDFT are considered and compared with standard methods. The article demonstrates the calculation of photoionization spectra using the Sternheimer approach and applies it to the photoionization spectrum of the Be atom. The results show significant improvement over traditional methods.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Julien Toulouse, Karno Schwinn, Felipe Zapata, Antoine Levitt, Eric Cances, Eleonora Luppi
Summary: This paper discusses the calculations of photoionization spectra and core resonances of open-shell systems using range-separated time-dependent density-functional theory. By employing the time-dependent range-separated hybrid and time-dependent locally range-separated hybrid schemes, along with a spin-unrestricted linear-response Sternheimer approach in a non-orthogonal B-spline basis set, efficient calculations can be performed and satisfactory results can be obtained.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Diata Traore, Emmanuel Giner, Julien Toulouse
Summary: The basis-set correction method based on density-functional theory corrects the energy calculated by a wave-function method with a given basis set by a density functional. This method accelerates the convergence of ground-state energies to the complete-basis-set limit by incorporating short-range electron correlation effects missing in the basis set. In this work, the method is extended to a linear-response formalism for calculating excited-state energies, and it is shown to significantly accelerate the basis convergence of excited-state total energies.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Physics, Nuclear
Julien Toulouse
Summary: We propose a semiclassical approximation method for calculating photoabsorption cross sections beyond the continuum threshold in quantum many-body systems. The method makes use of the fully quantum-mechanical Wigner function of the ground state and employs semiclassical expansions only for the part of the cross section that depends on the continuum states, avoiding the explicit calculation of these states. The results of testing the method in electronic-structure theory for the photoionization cross sections of hydrogen and helium atoms indicate that these semiclassical approximations can provide good estimates of cross sections at high energy.
EUROPEAN PHYSICAL JOURNAL A
(2023)
Article
Physics, Fluids & Plasmas
Antoine Bienvenu, Jonas Feldt, Julien Toulouse, Roland Assaraf
Summary: This study proposes a method to calculate physical properties using Monte Carlo calculations and conditional expectation values. By partitioning the physical space into subspaces or fragments and subsampling each fragment while freezing the environment, the conditional expectation values are obtained without introducing bias, and a zero-variance principle is maintained in the limit of separability. The method alleviates the usual bottleneck of Monte Carlo calculations in terms of scaling statistical fluctuations with the number of particles N, particularly for extensive observables.
