2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/128599Holes doped within the square CuO2 network specific to the cuprate superconducting materials have oxygen 2p character. We investigate the basic properties of such oxygen holes by wavefunction-based quantum chemical calculations on large embedded clusters. We find that a 2p hole induces ferromagnetic correlations among the nearest-neighbor Cu 3d spins. When moving through the antiferromagnetic background the hole must bring along this spin polarization cloud at nearby Cu sites, which gives rise to a substantial reduction of the effective hopping parameters. Such interactions can explain the relatively low values inferred for the effective hoppings by fitting the angle-resolved photoemission data. The effect of the background antiferromagnetic couplings of renormalizing the effective nearest-neighbor hopping is also confirmed by density-matrix renormalization-group model Hamiltonian calculations for chains and ladders of CuO4 plaquettes.Strongly Correlated Electronstext