The authors study the Anderson impurity model at T=0 taking into account double occupancy of the f-level. Particular emphasis is given to the limit when the f-level degeneracy Nf is large. In this limit there is an important asymmetry between the f0 and f2 configurations. They define a Kondo temperature delta u for Nf to infinity and relate delta u to the susceptibility and the f0 weight. delta u depends on the band width in a nontrivial way. It is shown that the valence photoemission spectrum can change substantially as double occupancy is taken into account.
 

Theory of Heavy Fermions and Valence Fluctuations. Proceedings of the Eighth Taniguchi Symposium Editor(s): Kasuya, T.; Saso, T. Berlin, West Germany: Springer-Verlag, 1985. p.110-19 of xii+287 pp. 23 refs. Conference: Shima Kanko, Japan, 10-13 April 1985 ISBN: 3-540-15922-3.