Many-body theory of BCC transition-metal surfaces

An exactly soluble many-body model for BCC transition-metal surfaces is presented within the context of a periodic small-cluster approach. The effort is concentrated on understanding the many-body effects dominated by strong short-range correlations among the d electrons. Applications to BCC Fe(001) and Co(001) surfaces are reported. The local-density-approximation band-structure results are taken as starting point. Interactions fully allowed by the atomic symmetry are built in using a tight-binding scheme. Many-body electronic structures, thermodynamic properties and inverse photoemission spectra have been calculated. Features induced by many-body effects have been obtained and discussed. (orig.)