Structure and Stability ofSi(114)−(2×1)

We describe a recently discovered stable planar surface of silicon, Si(114). This high-index surface, oriented 19.5° away from (001) toward (111), undergoes a $2\times 1$ reconstruction. We propose a complete model for the reconstructed surface based on scanning tunneling microscopy images and first-principles total-energy calculations. The structure and stability of $\mathrm{Si}\left(114\right)-(2\times 1)$ arises from a balance between surface dangling bond reduction and surface stress relief, and provides a key to understanding the morphology of a family of surfaces oriented between (001) and (114).