Non-monotonic lateral interactions in CO/Pt(111)

Adsorbate interactions of CO chemisorbed on Pt(111)

“…This approach predicts that the interaction between equivalent species will usually be repulsive, since some surface atoms will not be able to relax completely. This is indeed the case for on-top CO on Pt(111) considered here [9], and also for CO in three-fold hollow sites on Ni(111) [18]. Non-equivalent species, however, may interact attractively if the relaxation forces act in the same direction on some surrounding surface atoms, increasing the total relaxation energy.…”

“…The values in Ref. [9] were obtained by analysing the experimental adsorption isotherms using a transfer-matrix approach. They are for low coverages of adsorbed CO, up to 10%.…”

Monte Carlo simulation of CO and O coadsorption and reaction on Pt(111)

“…Redistribution of CO molecules over the sites with increasing coverage results in equal occupations of atop and bridge sites at h = 0.5, accompanied by formation of the c(4 · 2) film structure [10,14,[19][20][21]. Such a sequential occupation of the adsorption sites follows from theoretical evaluations [12,[15][16][17][18]20,21] as well as from results of infrared absorption spectroscopy for CO on Pt(1 1 1) [14]. All these features have been successfully reproduced in Monte Carlo simulations of CO adsorption kinetics and structures on the Pt(1 1 1) surface [22].…”

“…[11]) the ( p 3 · p 3)R30°CO structure on Pt(1 1 1) is observed. For CO adsorption on the Pt(1 1 1), the most recognized is the model of occupation of the on-top sites at low coverages (up to h = 0.33 [10,12,[14][15][16][17][18]) followed by occupation of the bridge sites. Redistribution of CO molecules over the sites with increasing coverage results in equal occupations of atop and bridge sites at h = 0.5, accompanied by formation of the c(4 · 2) film structure [10,14,[19][20][21].…”

Efficient Implementation of Cluster Expansion Models in Surface Kinetic Monte Carlo Simulations with Lateral Interactions: Subtraction Schemes, Supersites, and the Supercluster Contraction

“…In the CE, each cluster represents a pattern in which adsorbates are arranged on the surface, for instance, pairwise, three‐body, four body, and larger clusters. CE models are typically fitted to first‐principles calculations, although simple CEs have been successfully fitted to experimental temperature‐programmed desorption spectra and adsorption isotherms . The CE is, in principle, exact, but is always truncated in practical application due to constraints in the number of parameters that can be determined (and meaningfully fitted) on a first‐principles level.…”