Strand, Hugo U. R. 2014-10-07 We show that repulsive local Coulomb interaction alone can drive valence-skipping charge disproportionation in the degenerate d-band, resulting in effective negative-U. This effect is shown to originate from anisotropic orbital-multipole scattering, and it occurs only for d1,d4,d6, and d9 fillings (and their immediate surroundings). Explicit boundaries for valence-skipping are derived, and the paramagnetic phase diagram for d4 and d6 is calculated. We also establish that the valence-skipping metal is very different, in terms of its local valence distribution, compared to the atomiclike Hund's metal. These findings explain why transition-metal compounds with the aforementioned d-band fillings are more prone to valence-skipping charge order and anomalous superconductivity. application/pdf https://folia.unifr.ch/global/documents/304140 https://folia.unifr.ch/documents/304140/files/str_vsn.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevB.90.155108 info:eu-repo/semantics/openAccess License undefined Physical Review B. - 2014, vol. 90, no. 15, p. 155108 info:eu-repo/classification/udc/53 Valence-skipping and negative-U in the d-band from repulsive local Coulomb interaction http://purl.org/coar/resource_type/c_6501