2023/06/22 by Qiming Sun, Sun, Qiming · 1 citation
Physics and Astronomy · #Advanced Chemical Physics Studies #Atomic and Molecular Physics #Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Spectroscopy and Quantum Chemical Studies
paper · pdf · doi:10.48550/arxiv.2306.12764
openalex publication_date 2023/06/22 · openalex created_date 2023/06/24 · openalex updated_date 2026/07/28
Separating the Coulomb potential into short-range and long-range components enables the use of different electron repulsion integral algorithms for each component. The short-range part can be efficiently computed using the analytical algorithm due to the locality in both Gaussian-type orbital basis and the short-range Coulomb potentials. The integrals for the long-range Coulomb potential can be approximated with the density fitting method. A very small auxiliary basis is sufficient for the density fitting method to accurately approximate the long-range integrals. This feature significantly reduces the computational efforts associated with the N4 scaling in density fitting algorithms. For large molecules, the range separation and long-range density fitting method outperforms the conventional analytical integral evaluation scheme employed in Hartree-Fock calculations and provides more than twice the overall performance. Additionally, this method yields higher accuracy compared to regular density fitting methods. The error in the Hartree-Fock energy can be easily reduced to 0.1 μEh per atom, which is significantly more accurate than the typical error of 10 μEh per atom observed in regular density fitting methods.