The nonlocal correlation: A key to the solution of the CO adsorption   puzzle
  We study the chemisorption of CO molecule into sites of different coordination on (111) surfaces of late 4d and 5d transition metals. In an attempt to solve the well-known CO adsorption puzzle we have applied the relatively new vdW-DF theory of nonlocal correlation. The application of the vdW-DF functional in all considered cases improves or completely solves the discrepancies of the adsorption site preference and improves the value of the adsorption energy. By introducing a cutoff distance for nonlocal interaction we pinpoint the length scale at which the correlation plays a major role in the systems considered. 
P. Lazic, M. Alaei, N. Atodiresei, V. Caciuc, R. Brako, S. Blugel