Ab initio calculation of coverage-dependent adsorption properties of H on Pd(001).
The preferential adsorption sites, bond lengths, and vibration frequencies for H on the Pd (001) surface are determined by use of the ab initio pseudopotential local-orbital method. From the calculated total energies we derive a coverage-dependent adsorption energy in very good agreement with experiment. We establish that at low coverages (thetaless than or equal to1), H occupies fourfold hollow sites. At higher coverages (1