RESPONSE OF A STABILIZED-JELLIUM SURFACE TO A STATIC ELECTRIC-FIELD

The density-functional theory is employed to calculate the response of simple-metal surfaces, represented by the semiinfinite stabilized-jel lium model, to a static electric field oriented normal to the surface. The electron density distributions calculated self-consistently for t he neutral metal and in the presence of a weak external field are used to determine the first moments of the linear and second-order induced charge density distributions. The static image plane position determi ned by the centroid of the linearly induced density is compared with t he results for ordinary jellium. The calculated Rudnick-Stern paramete r, which is a measure of the normal component of the second-harmonic r esponse, is significantly reduced for high density metals and slightly increased for low density metals relative to the corresponding values for jellium.