1ST-PRINCIPLES CALCULATIONS OF THE SCREENING OF ELECTRIC-FIELDS AT THE ALUMINUM (111) AND (110) SURFACES

Using a self-consistent pseudopotential technique we calculate the distribution of screening charge at the Al(111) and (110) surfaces with perpendicular applied electric fields of up to 5 V angstrom-1 (with the metal charged positively). With increasing magnitude of the field the centre of gravity of the screening charge (the electrical surface) moves into the metal, although much less so than for the jellium model at the corresponding density. The major peak in the screening charge density profile narrows as the field is increased, in qualitative agreement with the results for the jellium model at a similar density and range of applied fields.