Cluster-model density functional study of a W-Cu(100) STM junction

In this article, we investigate the electronic properties of different clus ters modelling a tungsten tip, the Cu(100) surface and interacting W-Cu(100 ) systems in STM configuration. Electronic structure calculations are carri ed out within the LDA approximation of the Density Functional Theory (DFT). Both integrated (densities of states) and local properties (electronic den sity and electrostatic potential) are considered. The study is performed fo r top and hollow surface sites and two different tip-sample separations. (C ) 1999 Elsevier Science Ltd. All rights reserved.