Electronic structure of La$M$O$_3$ (M=Ti$\sim$Cu) by GW approximation

We investigate the electronic structure of La$M$O$_3$ ($M=$Ti$\sim$Cu) by GW approximation. The calculated spectra show good agreement with the experimentally observed ones. The on-site Coulomb interaction are affected by strong screening mechanism in trivalent transition metal ion systems, which is qualitatively different from those in mono-oxides $M$O of divalent transition metals. In trivalent transition metal ion systems La$M$O$_3$, 3d electrons are affected by deep atomic potential. Therefore, the 3d orbital locates energetically much nearer to O 2p levels than in $M$O. Moreover, in the cases of $M^{3+}$=Cr$^{3+}$, Mn$^{3+}$ and Fe$^{3+}$ systems, transition metal ions are well spin-polarized, and 3d levels locate very near to O 2p levels. As a result, these systems have large screening effects due to the extended d-electrons. In the cases of $M^{3+}$=Ni$^{3+}$ and Cu$^{3+}$, the systems are metallic and are affected by strong screening effects. In the other cases of $M^{3+}$= Ti$^{3+}$, V$^{3+}$, and Co$^{3+}$, there are small screening effects causing large static screened Coulomb interaction.