Self-consistent local-orbital method for calculating surface electronic structure: Application to Cu (100)

Abstract

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.

Adhesion at a heterophase interface: First-principles study of Mo(001)/MoSi2(001)

“…A vacuum space with a thickness of four times the lattice constant of bcc Mo is added to both sides of the slabs to form three-dimensional unit cells. This was found to greatly improve computational efficiency [3]. The localized basis set includes all of the core and valence orbitals.…”

“…Plots of the radial parts of the conduction-band local orbitals of Mo and Si are exhibited in figure l(a) and (b), respectively. The prescription used to obtain the basis set of Mo is the same as that used for other transition metals [3]. The 4p and 4d valence orbitals of Mo are fitted in the same way as the core orbitals.…”

“…The electronic structures and total energies of all of the interfacial configurations considered in this study are determined using the SCLO method [3] which has previously been successfully applied to the study of transition metal surfaces. The Ceperley-Alder [9] form of the exchangecorrelation potential is used in the local-densityfunctional single-particle equation [2].…”

“…The electronic structure and total energy of the Mo(001)-MoSi2(001) interface is calculated as a function of interfacial spacing by using the first-principles, self-consistent local orbital (SCLO) method [3]. To determine the adhesive energetics, the recemly proposed four-point method [4] is then employed to fit the calculated energy values at different interracial separations to a universalbinding-energy relation (UBER) [5].…”

Fizika kondensirovannogo sostoyaniya

“…3. Зарядовая плот-ность поверхностных сос-тояний медной «плиты» из 9 слоев, ориентируемой в направлении (100) 4 .…”