  Combining high-resolution core-level spectroscopy (HRCLS), scanning tunneling
microscopy (STM) and density-functional theory
  (DFT) calculations we reanalyze the Pd(100)-(SQRT(5) x SQRT(5) R27^o)-O
surface oxide phase. We find that the prevalent structural model, a rumpled
PdO(001) film suggested by previous low energy electron diffraction (LEED) work
(M. Saidy et al.,
  Surf. Sci. 494, L799 (2001)), is incompatible with all three employed
methods. Instead, we suggest the two-dimensional film to consist of a strained
PdO(101) layer on top of Pd(100). LEED intensity calculations show that this
model is compatible with the experimental data of Saidy et al.
