Multilayer relaxation of Cu(210) studied by layer-doubling LEED analysis and pseudopotential density functional theory calculations

Multilayer relaxation of Cu(210) surface has been studied by layer-doubling low energy electron diffraction (LEED) analysis and pseudopotential density functional theory (DFT) calculations. An excellent agreement between the calculated and measured I-V curves has been achieved as judged by direct inspection and a small Pendry R factor of 0.12. We suggest that the layer-doubling method is a suitable choice for quantitative LEED structural studies on high-index metal surfaces with interlayer spacings down to 0.8 Angstrom. Our pseudopotential DFT calculations have reproduced the relaxation sequence determined by the layer-doubling LEED analysis, i.e., - - + ..., with the largest quantitative discrepancy of about 0.04 Angstrom. Comparison is made with LEED and DFT studies on other high-index Cu surfaces. Based on this comparison, a general trend for multilayer relaxations of open metal surfaces is proposed.