Simulated scanning tunneling microscopy images of three-dimensional clusters: H₈Si₈O₁₂ on Si(100)-2×1

A scanning tunneling microscopy (STM) simulation based on the Bardeen perturbation method is used to generate simulated images of two possible chemisorption modes, monovertex and cracked cluster, for H₈Si ₈O₁₂ on Si(100)-2×1. The tip and sample are represented by cluster models, and electronic structure calculations are performed using density-functional theory. Simulated STM images are compared to experimental STM data acquired at nominally identical tunneling conditions. The simulated STM images elucidate the preferred monovertex attachment model, in addition to providing an understanding of the cluster features and apparent vertical and lateral dimensions observed in the experimental STM data.