Investigation of Some Ground State Properties of Lithium with the All Electron MAPW Method

Abstract

The electronic structure of lithium is evaluated by use of the LDA-MAPW self-consistent scheme and sophisticated exchange correlation functionals. From the volume dependence of the total energy the equilibrium lattice parameter, the bulk modulus, and the cohesion energy are derived. Various magnitudes characterising the shape of the Fermi surface are evaluated and compared with rather controversial experimental facts. The present investigations favour a Fermi surface relatively largely distorted. This conclusion is supported by calculations of the Compton profiles which are found in close accord with recent measurements of the directional Compton profiles by Schü lke et al.

Scaling behavior of the Compton profile of alkali metals

“…A considerable number of theoretical and experimental studies of Compton scattering have been carried out for Li (see Refs. [17,20,[25][26][27][28][29][30][31][32][33][34][35], and references therein). However, none of the experiments report measurement results above 4 atomic units (a.u.)…”

LDA and GGA Investigations of Some Ground-State Properties and the Compton Profile of Copper with the All-Electron MAPW Method

“…The electronic structure was self-consistently determined by use of the MAPW formalism yielding Bloch functions r | n k which due to their continuity within the atomic polyhedron are especially suited for the evaluation of the electron momentum density (EMD). For details we refer to previous investigations [10][11][12][13]. Complete self-consistent calculations for both the [Ne] and [Ar] cores are performed which treat 19 or 11 electrons, respectively, by the band structure scheme.…”

Special directions for surface integrals in cubic lattices with application to the evaluation of the COMPTON profile of copper

“…It is of relatively small extension as two directions only show marginal movement towards and from the plane y z = bounding the irreducible wedge, respectively. Thereby the residuum Our treatment satisfies this equation up to cubic harmonics 24 1 K , which contains at most an azimuthal dependence of the form cos (16 ) Φ . Therefore, it allows to evaluate the moments of the cubic harmonics up to 12 1 K , but not 12 2 K , .…”

“…Approximately 50 plane waves and 5 different radial functions for any value of the angular momentum 2 l £ are considered. For further details of the SCF calculation as well as the evaluation of the EMD we refer to previous investigations [16][17][18].…”

“…But integrals of this kind, in r-space, often occur in the course of self-consistent investigations, especially the evaluation of the Coulomb or the exchange-correlation potential when the atomic cell is divided into different parts by inscribed spheres (different versions of Slater's APW- [10][11][12], the KKR - [13,14], the LMTO- [15] method). Apart from such recent investigations within the MAPW scheme [16,17,19] the second method proves quite useful for evaluation of the electronic momentum density (EMD) and of the Compton profile (CP) [18,19]. These directions prom- ise to be also quite useful for solving the Boltzmann kinetic equation arising in a study of the electrical conductivity of metals having cubic symmetry.…”