Using BFS, a new semiempirical method for alloys, we study the surface
structure of fcc ordered binary alloys in the L1(2) structure (Ni3Al
and Cu3Au). We show that the surface energy is lowest for the mixed-co
mposition truncation of the low-index faces of such systems. Also, we
present results for the interlayer relaxations for planes close to the
surface, revealing different relaxations for atoms of different speci
es producing a rippled surface layer.