Extension and acceleration of relativistic density functional theory based on transformed density operator

Yasuhiro Ikabata, Takuro Oyama, Masao Hayami, Junji Seino, Hiromi Nakai

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1 Citation (Scopus)


We report an extension of relativistic density functional theory (RDFT) within one-component or two-component expressions that relies on a unitary-transformed density operator as well as a unitary-transformed Hamiltonian [Oyama et al., Chem. Phys. Lett. 680, 37 (2017)]. The transformed density operator is introduced to avoid the picture-change effect in the electron density, density gradient, kinetic energy density, and exchange-correlation potential. We confirmed that the implementation based on the spin-free infinite-order Douglas-Kroll-Hess method gives total, orbital, and excitation energies close to the reference values given by four-component RDFT calculations. To reduce the computational cost due to the transformed density operator, the local unitary transformation was also implemented. Numerical assessments revealed that the present scheme enabled the RDFT calculation of polyatomic systems with negligibly small picture-change effect.

Original languageEnglish
Article number164104
JournalJournal of Chemical Physics
Issue number16
Publication statusPublished - 2019 Apr 28


ASJC Scopus subject areas

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

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