A relativistic density-functional theory based on a Fock-space effective quantum-electrodynamics (QED) Hamiltonian using the Coulomb or Coulomb-Breit two-particle interaction is developed. This effective QED theory properly includes the effects of vacuum polarization through the creation of electron-positron pairs but does not include explicitly the photon degrees of freedom. It is thus a more tractable alternative to full QED for atomic and molecular calculations. Using the constrained-search formalism, a Kohn-Sham scheme is formulated in a quite similar way to non-relativistic density-functional theory, and some exact properties of the involved density functionals are studied, namely charge-conjugation symmetry and uniform coordinate scaling. The usual no-pair Kohn-Sham scheme is obtained as a well-defined approximation to this relativistic density-functional theory.

中文翻译：

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基于有效量子电动力学的相对论密度泛函理论

建立了相对论密度泛函理论，该理论基于使用库仑或库仑-布赖特两粒子相互作用的福克空间有效量子电动力学（QED）哈密顿量。这种有效的QED理论适当地包含了通过创建电子-正电子对而产生的真空极化效应，但并未明确包括光子自由度。因此，对于原子和分子计算，它是完整QED的更易于处理的选择。使用约束搜索形式主义，以与非相对论密度泛函理论非常相似的方式制定了Kohn-Sham方案，并研究了所涉及的密度泛函的一些确切性质，即电荷共轭对称性和均匀坐标缩放。