FIRST-PRINCIPLES CALCULATIONS FOR WORK FUNCTION AND SURFACE-ENERGY OFTHIN LITHIUM FILMS

Surface relaxation, electronic work function and surface energy for (1 00), (110) and (111) surfaces of bce Li are calculated using a first-p rinciples molecular dynamics method. The obtained relaxations for thre e-layer Li slabs are outward for the (100) and inward for the (110) an d (111) surface layers. The results show that the work function increa ses in the order (100), (111) and (110) in the surface orientation. Fu rthermore, the results suggest that, with increasing number of atomic layers, the various energy quantities converge rather fast to values t hat are within only a few percents of their semi-infinite bulk results , although the surfaces of the slabs, with less than ten atomic layers , still interact.