First-principles calculation of the atomic structure of one-dimensional indium chains on Si(111): Convergence to a metastable structure

A recent first-principles calculation [Phys. Rev. Lett. 96, 136101 (2006)] carried out by Gonzalez reported the origin of the observed reversible (4x1)<->(8x2) phase transition in quasi-one-dimensional indium chains on the Si(111) surface. Gonzalez claimed that this phase transition would be driven by the dynamical fluctuations between four degenerate insulating 4x2 structures which are the building blocks of the 8x2 structure. This may provide an explanation for the controversial issue that the low(high)-temperature phase is insulating (metallic). However, our first-principles calculations show that such an insulating 4x2 structure obtained by Gonzalez is not stabilized but converged to a metastable structure whose structural and electronic properties are similar to those of the metallic 4x2 structure obtained by previous first-principles calculations.