Ab initio cluster and band structure calculations on systems modeling La2CuO4. Effects of charge transfer between the different planes, Madelung potentials, doping and correlations

摘要: Abstract Based on an initio Hartree-Fock (HF) calculations both the cluster and aand structure level, electronic of La 2 CuO 4 (2-1-4) was investigated. As model systems [CuO 6 ] n − (cluster case) m units (band were chosen, i.e. “apical” oxygens explicitly included. Surrounding ions treated as point charges via partially self-consistent Madelung potentials case), respectively. Using HF approximation we found a too low density states (DOS) around Fermi while charge distribution in ground state seems to be reasonable. To obtain DOS curves comparable with experimental ones, had go beyond one-particle description by using Moller-Plesset many-body perturbation theory. A comparison functional (DF) local (LDA) is given. Finally, studied effects doping level. Here that upon holes ω symmetry predominant oxygen character are formed within planes 2-1-4. At same time increasing covalent bonding between in-plane Cu O observed.