Solution of the Anderson model in the context of chemisorption

We present a solution of the Anderson model for chemisorption which—for the single-particle Green's function of the adsorbate—becomes exact in three limiting cases: (i) the intra-atomic Coulomb repulsion $U$ tends to zero, (ii) the hopping term $B$ tends to zero (weak-coupling limit), (iii) the bandwidth $V$ tends to zero, i.e., our solution yields the exact strong-coupling limit (symmetric and asymmetric) and thus complements the solution given recently by Brenig and Schönhammer.