Mechanism for the valence-band photoemission in Ni: Inclusion of interatomic interactions

In relation to the valence-band photoemission in Ni, the importance of interatomic interactions is proposed, on the basis of examinations of the correlation effect in the $T$-matrix approximation. Calculated results show that, in the presence of the interatomic interaction, both the bandwidth and the satellite binding energy become smaller than those in the Hubbard model. This property in the interatomic interaction enables us to explain consistently the experimental result.