Non-Linear Self-consistent Calculation of the Electron Density Distribution in Metallic Lithium

Abstract

<p>An approximate non-linear self-consistent calculation of the charge density distribution about a point charge of Z=3, appropriate to lithium, imbedded in an electron gas of mean density equal to the free electron gas density of metallic lithium has been carried out. The major difference between this and previous work on lithium now in the literature is the manner in which the two core electrons have been treated. The previous work simply considered the screened potential of an Li⁺ ion and solved for the "valence" charge density in the presence of that potential. The present procedure has included these bound electrons in obtaining self-consistency; these states therefore have the wave functions appropriate to the metal instead of the free atom.</p> <p>We have also gone beyond the previous work in that approximate corrections for correlation as well as exchange effects among the electrons have been included.</p> <p>Because the neighbouring ions present in the solid affect the electron charge distribution, these results represent an approximation to the true density distribution of the metal. However, to a large extent, the ions are well separated, so this is expected to be a reasonable approximation, in particular in regions very near the ion. Because of this, the results are used to calculate the Knight shift, and good agreement with experiment is obtained.</p>