Structural model for the Si(111)-4×1-In reconstruction

A $\pi$-bonded-chain-stacking-fault $(\pi$-SF) model is proposed for the Si(111)4$\times$1-In surface structure. The model incorporates 4$\times$1 Si(111) substrate reconstruction consisting of the sixfold Si rings in the faulted-unfaulted sequence connected through fivefold and sevenfold Si rings. Indium atoms (0.75 ML) reside above sixfold and fivefold Si rings while sevenfold Si rings form $\pi$-bonded chains between In ridges.