14 Externe wissenschaftliche Einrichtungen

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/15

Browse

Institute: search.filters.UBSInstitut.Max-Planck-Institut für Intelligente SystemePublication Type: search.filters.UBSTyp.Zeitschriftenartikel

Search Results

Now showing 1 - 7 of 7
  • Thumbnail Image
    ItemOpen Access
    Cohesive properties of bcc and fcc rubidium from ab initio pseudopotentials
    (1985) Maysenhölder, Waldemar; Louie, Steven G.; Cohen, Marvin L.
    Total-energy calculations have been performed for Rb at zero temperature using a self-consistent ab initio pseudopotential approach within a local-density-functional scheme. The energy difference between fcc and bcc Rb, and the energy barrier between these structures, are found to be extremely small near the equilibrium volume. Agreement of the calculated cohesive properties of bcc Rb with experimental values is good in view of the softness of the material. A transition from bcc to fcc has been calculated to occur at a pressure of about 52 kbar for T=0 K, which compares favorably with the observed value of 70 kbar for this transition at room temperature.
  • Thumbnail Image
    ItemOpen Access
    Calculations of point-defect properties in copper, silver, and gold based on three-body interactions
    (1982) Bauer, Rolf; Maysenhölder, Waldemar; Seeger, Alfred
    Long-term trends in the calculation of defect properties in the noble metals are criticezed. On physical grounds it is argued that the model potentials used should allow for many-body interactions. Results based on potentials which include three-body interaction terms are presented for Cu, Ag, and Au.
  • Thumbnail Image
    ItemOpen Access
    On the determination of interaction parameters from correlations in binary alloys
    (1987) Maysenhölder, Waldemar
    The determination of interaction parameters from correlation functions in binary alloys is discussed by means of high-temperature expansions for the correlations. The inherent nonlinearity of this "inverse problem" of statistical mechanics leading to non-unique solutions is emphasized. The formulation includes pair and triplet interactions. Some results of a specific "inverse Monte Carlo calculation" are criticized. The paper provides a collection of formulae, especially for probabilities and correlations, which should prove useful for clarifying the subject.
  • Thumbnail Image
    ItemOpen Access
    Two subroutines for calculating lattice sums and the distortion field due to a point force in hexagonal systems
    (1981) Maysenhölder, Waldemar
    The subroutines ARRANGE and DISPL contained in HEXALAT have been developed for application of solid state theory to hexagonal crystals, in particular to the hexagonal closed packed (hcp) structures. ARRANGE generates the coordinates of a roughly estispherical arrangement of atoms which occupy regular sites of an hcp structure, and thus provides a means for calculating lattice sums very easily.
  • Thumbnail Image
    ItemOpen Access
    The Eshelby factor for cubic crystals with arbitrary elastic anisotropy
    (1984) Maysenhölder, Waldemar
    The Eshelby factor for cubic crystals has been calculated for arbitrary anisotropy. One of the two integrations needed could be performed analytically. An expansion up to 4th order in the anisotropy and exact results for special cases are also given.
  • Thumbnail Image
    ItemOpen Access
    Effect of three-body interactions on the formation entropy of monovacancies in copper, silver and gold
    (1985) Maysenhölder, Waldemar; Bauer, Rolf; Seeger, Alfred
    The vacancy formation entropy in Cu, Ag and Au is estimated from model calculations with explicit treatment of three-body interactions. The three-body interactions cause a rather strong relaxation around the vacancies and therefore lead to lower values for the formation entropy than usual pair-potential calculations.
  • Thumbnail Image
    ItemOpen Access
    Lowest-order approximations to relaxation volumes of monovacancies in cubic metals from pair potentials and Finnis-Sinclair potentials
    (1986) Maysenhölder, Waldemar
    Relaxation volumes of point defects in cubic metals can be conveniently estimated by differentiating approximate formation energies with respect to the lattice constant. Lowest-order analytical expressions for monovacancies have been derived for equilibrium pair potentials and for the N-body potentials of Finnis and Sinclair (1984). These expressions may be evaluated with little effort and prove far superior to other lowest-order approximations to vacancy relaxation volumes.