Experimental tests of new direct methods for adsorbate structure determination using photoelectron diffraction

Two recently proposed methods for approximate but direct adsorbate site determination using scanned‐energy mode photoelectron diffraction data have been tested on experimental data from three different adsorption systems. The three systems studied, O, CO, and C2H4 on Ni(111) involve three different local adsorption sites (single hollow, mixed hollows and near‐atop) and have all been subjected to separate full quantitative structure determinations. Both the simple Fourier transform approach of Fritsche and Woodruff, and the projection method of Hofmann and Schindler are found to correctly identify all the adsorption sites. The precision of these approximate structure determinations, and the size of the data bases used, are compared with each other and with other proposed methods