The magnetic coupling constants of KCuF3, Sr2CuO2Cl2, La2CuO4, La2NiO4, K2NiF4, KNiF3, NiF2, KMnF3, and MnF2 are calculated with a hybrid density functional, in which 35% of the nonlocal Hartree-Fock exchange is mixed in the general gradient approximation to the density functional theory. The theoretical magnetic coupling constants for these materials with different structures, spins, and magne...

Multiple functional ionic and electronic orders are observed in high temperature superconducting cuprates. The static charge density wave order is one of them and it is spatially localized in different spatial regions of the material. It is also known that the oxygen interstitials introduced by chemical intercalation self-organize in oxygen rich space in the spacers and hole rich space in the C...

Dome-shape superconductivity phase diagram can commonly be observed in cuprateand iron-based systems via tuning parameters such as charge carrier doping, pressure, bond angle, and etc. We report doping electrons from transition-metal elements (TM = Co, Ni) substitution can induce high-Tc superconductivity around 35 K in Ca0.94La0.06Fe2As2, which emerges abruptly before the total suppression of ...

Accurate ab initio calculations on embedded Cu4O12 square clusters, fragments of the La2CuO4 lattice, confirm a value of the nearest neighbor antiferromagnetic coupling (J=124 meV) previously obtained from ab initio calculations on bicentric clusters and in good agreement with experiment. These calculations predict non negligible antiferromagnetic secondneighbor interaction (J =6.5 meV) and fou...

Coulomb interaction between electrons on p-orbitals of oxygen atom in strongly correlated compounds is not negligible, since its value (Up) has comparable order of magnitude with the value of Coulomb interaction on dorbitals of transition metal atom (Ud). We investigate the effect of taking into account Coulomb correlations in oxygen p-shell in addition to the correlations in the transition met...

First-principles band structure calculations for large supercells of Ba2CuO4−δ and La2CuO4−δ with different distributions and concentrations of oxygen vacancies show that the effective doping on copper sites strongly depends on where the vacancy is located. A vacancy within the Cu layer produces a weak doping effect while a vacancy located at an apical oxygen site acts as a stronger electron do...