Electronic structure of by means of local-density approximation plus strong correlation effects

The electronic structure of (Formula presented) according to experimental spectroscopic data presents strong correlation in the electrons at energies close to (Formula presented) We investigate this point by analyzing the electronic structure calculated from several complementary procedures. The first of these is performed by means of the local density approximation (LDA). In a second calculation we develop an (Formula presented) calculation and finally, we include the self-energy effects obtained from a multiband Hubbard model. Our results for the first calculation are similar to those previously performed within the LDA, and these results are used for obtaining the self-energy effects included in the second calculation. The inclusion of these effects yields an electronic structure that seems to be in reasonable agreement with spectroscopic experimental data. © 2000 The American Physical Society.