Relaxation of the Mo(112) and W(112) surfaces

Relaxation of the Mo(112) and W(112) surfaces has been simulated within DFT in local density approximation. It has been found that the surface relaxation, which can be described as a 14% contraction of the topmost surface layer with a small (0.1%) shift of surface atomic rows, results in a strong decrease of the surface energy with respect to the bulk truncated crystal surfaces (from 0.2 to 0.17 eV/Å2 for the Mo(112) and from 0.36 to 0.33 eV/Å2 for the W(112)). The surface relaxation is accompanied by the redistribution of the surface density of states, associated with the transformations of surface states.