ELECTRONIC BAND-STRUCTURE AND LATTICE DISTORTION IN PEROVSKITE TRANSITION-METAL OXIDES

The electronic structures of LaMO3 (M = Ti, V,...,Cu) are reviewed wit h particular attention to the effect of the lattice distortion. The FL APW and LMTO methods are employed in the band structure calculations i n the LSDA, GGA and LDA+U schemes. The experimental lattice parameters are used in these calculations. The change of the bond angle of M-O-M gives rise to the change of the width of the d band. For LaVO3 and La MnO3 with cooperative Jahn-Teller distortions, the LDA and/or GGA calc ulations produce orbital orders, which determine the types of spin ord ers. The LaTiO3 system has no Jahn-Teller distortion, where the spin-o rbit coupling might play an important role.