LAUSR

The correlated electronic structure of the infinite-layer compounds ${\mathrm{NdNiO}}_{2}$ and ${\mathrm{SrCuO}}_{2}$ at stoichiometry and with finite hole doping is compared. Key differences are elucidated from an advanced first-principles many-body perspective. Contrary to the charge-transfer insulating cuprate, the self-doped nickelate remains noninsulating even for large interaction strength, though the Ni-${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ spectral weight is also gapped in that limit. Hybridization between $\mathrm{Ni}(3d)$ and $\mathrm{Nd}(5d)$ is crucial for the appearance of the self-doping band. Upon realistic hole doping, ${\mathrm{Sr}}_{1\ensuremath{-}y}{\mathrm{CuO}}_{2}$ shows the expected mixed oxygen-Cu-${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ (Zhang-Rice) states at low energy. In the case of ${\mathrm{Nd}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{NiO}}_{2}$, the self-doping band is shifted to higher energies and a doping-dependent ${d}_{{z}^{2}}$-versus-${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ competition on Ni is revealed. The absence of prominent Zhang-Rice physics in infinite-layer nickelates might be relevant to understand the notable difference in the superconducting ${T}_{\mathrm{c}}$'s.