We study the surface core-level shifts (SCLS's) at the W(320) surface by ab
initio calculations, including both initial-state and final-state effects.
This stepped surface features (110) terraces with five atom rows, separate
d by single atomic steps. We find that the final-state effect is important
for the proper prediction of the SCLS at the W(320) surface. Unlike the W(1
10) surface where the final-state effect increases the SCLS to lower bindin
g energy, the reverse is true in the W(320) surface, indicating inefficient
core-hole screening at the stepped surface. Our results provide a theoreti
cal basis for the interpretation of core-level photoemission spectra from t
he W(320) surface.