ACCURATE CALCULATION OF ATOMIC RESONANCES NEAR SURFACES

We present first results of new accurate calculations for atomic reson ances near an Al surface. We employ large-scale matrix diagonalization involving greater than or equal to 1000 basis states and realistic ef fective single-particle potentials. We implement two complementary tec hniques - the complex rotation method and the stabilization method. We also investigate strongly perturbed atomic wave functions near the su rface and relate their evolution as a function of the distance, d, to the Wigner-von-Neumann non-crossing rule. The distance dependence of t he resonance parameters can be analyzed in terms of semiclassical mech anics.