Physics of the Be(10(1)over-bar0) surface core level spectrum

Photoelectron diffraction has been utilized to confirm the theoretical prediction that the surface core level shifts observed for Be(<10(1)over bar 0>) have been improperly assigned. The original assignment based upon the relative intensity of the shifted components was intuitively obvious: the peak with the largest shift of -0.7 eV with respect to the bulk was associated with the surface plane, the next peak shifted by -0.5 eV stems from the second layer, and the third peak at -0.22 eV from the third and fourth layers. First-principles theory and our experimental data show that the largest shift is associated with the second plane, not the first plane. [S0031-9007(98)07350-5].