Calculation of effective Coulomb interaction in PrCoO3

It is very essential to know the suitable value of effective coulomb interaction (U_eff) which will be material specific, if one wants to learn about various physical features of strongly correlated systems in an extensive manner. In present work, the constrained density function theory (DFT) method has been used to evaluate the suitable U_eff value between the localized electrons for 3d and 4f orbitals in strongly correlated system. For the evaluation of suitable U_eff, the d/f-linearization energy (E_d/f) is very important and is found to be >= 44 eV above Fermi level. The U_eff is predicted by local density approximation (LDA) functional for both the impurity atoms separately are found to be Co (3d electrons) ∼ 6.3 eV and Pr (4f electrons) ∼ 7.0 eV for E_d/f ∼ 44 eV above Fermi level. The U_eff value for Pr (4f electrons) is higher than Co (3d electrons). This indicates that Pr 4f electrons is more localized than Co 3d electrons in PrCoO₃ compound.