Using the film–linear-augmented-plane-wave method, we propose a set of improved basis functions for the vacuum-jellium region in a jellium-slab model. With a W slab of three layers, the work function of a W(001) surface covered with a Cs layer is calculated with use of this method. The work-function–coverage curve obtained is in much better agreement with experiment than previous work. This calculation shows that this method is more stable and accurate than previously published ones on both a covered surface and a clean surface.

• Received 22 April 1991

DOI:https://doi.org/10.1103/PhysRevB.44.8942