Quantum-size effect in thin Al(110) slabs

The work function and surface energy have been calculated for relaxed thin Al(110) slabs using local density-functional theory, first-principles pseudopotentials and a plane-wave basis set. A significant quantum-size effect (QSE) exhibited by both these quantities as well as surface relaxation can be interpreted on the basis of existing jellium calculations. Our calculations show that the QSE persists for slabs up to 15 to 16 atomic layers thick. So even for thick slabs, oriented with the open (110) surface plane, the calculated surface quantities are given with some uncertainty due to the QSE.