Movement of a tungsten adatom on the W(112) surface

Investigation of a single adatom as well as cross–channel infinite chain movement on the W(112) surface has been performed using ab initio methods. The energetics of the isolated adatom has been derived and is in very good agreement with experimental data. The asymmetry of the potential barrier associated with a lateral displacement of the W(112) surface is clearly identified. Surprisingly, the movement of an adatom in a cross–channel chain is only slightly more demanding than the movement of a single adatom, showing the importance of compensation effects for diffusion. The differences in the minimum energy paths of adatoms are discussed.