Calculated adsorbate-induced surface stress

Table 11. Calculated adsorbate induced surface stress on Pt(l 11).

DFT calculations were used to quantify the different interactions. All interactions were found to be repulsive. The most repulsive interactions were along the copper rows (in the [lIO] direction), due to a through-surface interaction between carboxylate groups of different tartaric acid molecules binding next to each other. In addition to these interactions we have proposed the existence of an adsorbate-induced surface stress which reduces the binding energy when more than three tartaric acid molecules bind to the same copper row. This surface stress causes the empty troughs in the (9 0,1 2) ordered structure. ... 

Table 8. Calculated adsorbate-induced changes of stress on semiconductor surfaces...

First principles calculations of the effect of gas adsorption on the surface stress of Pt(lll) have been performed [97Fei], The adsorption of hydrogen and oxygen was found to relief the tensile stress of the clean Pt(l 11) surface partially. The results of this study are presented in section 4.4.7.11 in Table 11 and in Fig. 11 and Fig. 12. These calculations suggest that the modification, i.e. weakening, of the surface bonds of the substrate in the vicinity of the adsorbate is an important issue in the discussion of adsorbate-induced stress. 

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