Electronic structure of new RENiAsO (RE = Rare Earth Elements) compounds: Ab initio spin-density functional theory

RENiAsO compounds have been studied by using density-functional theory with the local spin-density approximation (LSDA). In order to take into account the strong on-site Coulomb interaction U present in RENiAsO, we also performed the LSDA+U calculations. We investigated the electronic structure with on-site Coulomb potential for the RE-derived 4f orbitals and Ni-derived 3d to obtain the correct ground state of REFeAsO. The structural parameters, density of states and band structures have been given in detail. Overall, the technique developed and tested in this work holds promise in enabling accurate and fully predictive calculations of strongly correlated electron materials. A detailed analysis shows that the LSDA+U method provides the better description of our systems. No experimental or ab-initio study was related to this series of materials.