Vibrations of Adsorbed Atoms and Molecules

By monitoring the vibration spectra of chemisorbed species as a function of coverage, crystal surface, and temperature, the location and site symmetries of the adsorbed atoms (4-fold, 3-fold, bridge, on-top) can be monitored and variations in site occupancy can be determined. 

Adsorbed molecules that form chemical bonds with surface atoms exhibit vibrations of the surface chemical bond as well as within the bonds in the molecule. Carbon monoxide chemisorbed on various metal surfaces is the most frequently studied molecular adsorbate system. CO molecules, which adsorb usually with the CO 

TABLE 4.2. CO Adsorption Sites (Determined by LEED) and C-O Stretch Frequencies 

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