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The energy bands for the 3d and 4s states of copper and the 2p states of aluminum are calculated by the augmented-plane-wave method. The crystal charge density is calculated for copper and aluminum and is used to find the scattering factors. For copper these factors are in better agreement with experiment than are those determined from Hartree-Fock atomic calculations. This improvement is shown to be due to the fact that the copper valence-electron charge density is more spread out in the solid than in the atom. The calculated scattering factors are sensitive to the starting crystal potential because of the difficulty of handling exchange in the solid. For aluminum, no improvement over Hartree-Fock scattering factors is realized by performing an energy-band calculation.* Based on work submitted as partial fulfillment of the Ph.D. requirements at Massachusetts Institute of Technology. 1

A method is introduced for computing the self-consistent electronic structure of solid surfaces or any other periodic defect array. Results are obtained for the Cu (100) surface. The computed electron work function is in excellent agreement with experiment. A large density of surface states is found to be split off from the upper 3d-band edge. This large density of surface states has not been seen before theoretically, presumably because these states are sensitive to self-consistency. Surface-state and total-charge-density plots show that a significant fraction of the density in the surface layer is due to electrons in these surface states.Their existence is corroborated by photoemission difference spectra taken for chemisorbed nitrogen, oxygen, and sulfur on Cu (100). A prominent surface-state band among these states which was found theoretically has subsequently been isolated by angular photoemission. The dispersion and energy location of the experimental result agrees very well with the theoretical prediction. Further insight into surface-electronicstructure properties is provided by results for local and total densities of states as a function of film thickness, one to nine atomic layers.

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The spin-polarized electronic energy bands, densities of states, and magnetic moments of the intermetallic compounds YCo"SmCo"and GdCo, are calculated by a self-consistent augmented-plane-wave method, The results are similar in the three cases, with the computed magnetic moments in reasonable agreement with experiment. Only about one electron (of a possible three) is transferred from the rare earth to cobalt, leaving the minority-spin cobalt 3d band unfilled, and the moment high. There is evidence of d-d coupling between cobalt and the rare earth, providing information as to why experiments designed to reverse the antiparallel spin coupling between the two sublattices by manipulation of the electron concentration have been unsuccessful.