Electronic structure and magnetism in infinite-layer nickelates RNiO2 (R = La-Lu)

Using first-principles calculations, we analyze the evolution of the electronic structure and magnetic properties of infinite-layer nickelates RNiO2 (R = rare earth) as R changes across the lanthanide series from La to Lu. By correlating these changes with in-plane and out-of-plane lattice parameter reductions, we conclude that the in-plane Ni-O distance is the relevant control parameter in infinite-layer nickelates. An antiferromagnetic ground state is obtained for all RNiO2 (R = La-Lu). This antiferromagnetic state remains metallic across the lanthanide series and is defined by a multi-orbital picture with low-energy relevance of a flat Ni-d(z)2 band pinned at the Fermi level, in contrast with cuprates. Other non-cuprate-like properties such as the involvement of R-d bands at the Fermi level and a large charge-transfer energy are robust for all RNiO2 materials.