NIXSW normal incidence X-ray standing

Acronyms XSW X-ray standing wave, NIXSW normal incidence X-ray standing wave. 

It was nevertheless important to verify this unusual structure by independent experimental methods. This was achieved by a normal-incidence x-ray standing wave (NIXSW) [45, 49] study in 1992, a LEED study [17] in 1994, and in an STM study [50] in 1995. Fig. 7 shows a comparison of experimental LEED spectra with spectra calculated for the Al(l 11)—( 3 x, /3)/ 30°—Na structure with Na atoms adsorbed in substitutional sites. 

Recently, the method has been combined with an energy-resolved detection of the corresponding photoelectrons, which makes it possible to determine the geometric position of one type of atom in different chemical environments separately. Eor example in the case of PF3 adsorbed on Ni(lll) this so called chemical-shift normal incidence X-ray standing wave (CS-NIXSW) technique makes it possible to determine the position of three different P-species independently [99JAC]. 

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