Relativistic two-electron repulsion operator formulas for the Douglas–Kroll method

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Two-electron repulsion operator formulas for the second- and third-order Douglas–Kroll (DK2 and DK3) method were derived and implemented. The formulas were applied to helium-like ions with Z = 10, 20, …, 130, and to rare gas atoms. The energies obtained for the DK2 and DK3 two-electron operators showed differences from the four-component method that were one order of magnitude smaller than those of the nonrelativistic and DK1 two-electron operators. Approximation formulas for the small component-type two-electron integrals were also derived; they were applied to the helium-like ions with Z = 80 and 130 and were numerically confirmed to reproduce unapproximated values very accurately.

Original languageEnglish
Article number138158
JournalChemical Physics Letters
Publication statusPublished - Jan 2021

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry


Dive into the research topics of 'Relativistic two-electron repulsion operator formulas for the Douglas–Kroll method'. Together they form a unique fingerprint.

Cite this