TY  - JOUR
AU  - Seth, Priyanka
AU  - Peil, Oleg E.
AU  - Pourovskii, Leonid
AU  - Betzinger, Markus
AU  - Friedrich, Christoph
AU  - Parcollet, Olivier
AU  - Biermann, Silke
AU  - Aryasetiawan, Ferdi
AU  - Georges, Antoine
TI  - Renormalization of effective interactions in a negative charge transfer insulator
JO  - Physical review / B
VL  - 96
IS  - 20
SN  - 2469-9950
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2017-08362
SP  - 205139
PY  - 2017
AB  - We compute from first principles the effective interaction parameters appropriate for a low-energy description of the rare-earth nickelate LuNiO3 involving the partially occupied eg states only. The calculation uses the constrained random-phase approximation and reveals that the effective on-site Coulomb repulsion is strongly reduced by screening effects involving the oxygen-p and nickel-t2g states. The long-range component of the effective low-energy interaction is also found to be sizable. As a result, the effective on-site interaction between parallel-spin electrons is reduced down to a small negative value. This validates effective low-energy theories of these materials that were proposed earlier. Electronic structure methods combined with dynamical mean-field theory are used to construct and solve an appropriate low-energy model and explore its phase diagram as a function of the on-site repulsion and Hund's coupling. For the calculated values of these effective interactions, we find that in agreement with experiments, LuNiO3 is a metal without disproportionation of the eg occupancy when considered in its orthorhombic structure, while the monoclinic phase is a disproportionated insulator.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000415889800002
DO  - DOI:10.1103/PhysRevB.96.205139
UR  - https://juser.fz-juelich.de/record/841270
ER  -