Several approaches are presented to improve the efficiency of Hartree-Fock and Kohn-Sham self-consistent field (SCF) calculations relying on a simple first-order energy correction reminiscent of the scheme used in dual-basis SCF methods. The basic idea is to perform an initial SCF calculation computing approximate Fock-matrices and, in the final iteration step, to use a more complete Fock-matrix builder together with the energy correction to diminish the error. The approximation is tested for conventional and local density fitting (DF) SCF approaches combining various auxiliary basis sets, fitting metrics, and Fock-matrix construction algorithms in the initial and final iterations as well as for seminumerical SCF methods combining integration grids of different qualities. We also report the implementation of the occupied orbital resolution of identity exchange construction algorithm with local DF approximations. Benchmark calculations are presented for total energies, reaction energies, and molecular geometries. Our results show that speedups of up to 80% can be expected utilizing the new approaches without significant loss of accuracy.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1063/5.0041276 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Effect of Exact Exchange on the Energy Landscape in Self-Consistent Field Theory.
J Chem Theory Comput
January 2025
Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
Density functional approximations can reduce the spin symmetry breaking observed for self-consistent field (SCF) solutions compared to Hartree-Fock theory, but the amount of exact Hartree-Fock (HF) exchange appears to be a key determinant in broken symmetry. To elucidate the precise role of exact exchange, we investigate the energy landscape of unrestricted Hartree-Fock and Kohn-Sham density functional theory for benzene and square cyclobutadiene, which provide paradigmatic examples of closed-shell and open-shell electronic structures, respectively. We find that increasing the amount of exact exchange leads to more local SCF minima, which can be characterized as combinatorial arrangements of unpaired electrons in the carbon π system.
View Article and Find Full Text PDFDirect Givens rotation method based on error back-propagation algorithm for self-consistent field solution.
J Chem Phys
January 2025
Department of Chemistry and Biochemistry, School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan.
The self-consistent field (SCF) procedure is the standard technique for solving the Hartree-Fock and Kohn-Sham density functional theory calculations, while convergence is not theoretically guaranteed. Direct minimization methods, such as the augmented Lagrangian method (ALM) and second-order SCF (SOSCF), obtain the SCF solution by minimizing the Lagrangian with the gradient. In SOSCF, molecular orbitals are optimized by truncating the Taylor expansion of a unitary matrix represented in exponential form to ensure the orthonormality condition.
View Article and Find Full Text PDFPerformance of quantum chemistry methods for a benchmark set of spin-state energetics derived from experimental data of 17 transition metal complexes (SSE17).
Chem Sci
December 2024
Jagiellonian University, Faculty of Chemistry Gronostajowa 2 30-387 Kraków Poland +48 12 686 24 89.
Article Synopsis
- Accurate prediction of spin-state energetics for transition metal complexes is crucial for understanding catalytic mechanisms and discovering new materials, but existing methods are often unreliable due to their strong dependency on the computational approach.
- A new benchmark set of spin-state energetics was created from experimental data of 17 transition metal complexes (Fe, Co, Mn, Ni), which helps establish reference values for comparing computational methods like DFT and coupled-cluster theories.
- The study found that the coupled-cluster CCSD(T) method is the most accurate, outperforming multireference methods, while certain double-hybrid DFT methods also showed promising results compared to commonly recommended DFT approaches that performed significantly worse.
A Critical Evaluation of the Hybrid KS DFT Functionals Based on the KS Exchange-Correlation Potentials.
J Phys Chem Lett
October 2024
Institute of Physics, Faculty of Physics, Astronomy, and Informatics, Nicolaus Copernicus University in Toruń, ul. Grudzia̧dzka 5, 87-100 Toruń, Poland.
We have developed a critical methodology for the evaluation of the quality of hybrid exchange-correlation (XC) density functional approximations (DFAs) based on very fundamental quantities, i.e., Kohn-Sham (KS) XC potentials, self-consistent electron densities, first ionization potentials (IPs), and total energies.
View Article and Find Full Text PDFJump discontinuities of finite-basis-set exchange-correlation potentials at atomic nuclei.
J Chem Phys
September 2024
Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada.
The kinetic energy density of electrons and the gradient of the electron density have pronounced jump discontinuities at the positions of the atomic nuclei in molecules. Certain exact relations then imply that molecular Kohn-Sham exchange-correlation potentials may also be discontinuous at atomic nuclei. Here, we confirm that exchange-correlation potentials derived from Hartree-Fock and correlated wavefunctions within Slater-type basis sets do exhibit such discontinuities.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!