title: Sharp corners in the cross section of ultrathin Si nanowires.
abstract: We have determined stable geometries for pristine Si nanowires grown along their 100 axis through systematic density functional studies. Strikingly, Si nanowires with diameters smaller than 1.7 nm prefer a shape that has a square cross section. This stems from dimerization between corner atoms and also from benign reconstruction patterns that maximally saturate Si dangling bonds.
authors.affiliation: Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
authors.forename: J X
authors.initials: JX
authors.lastname: Cao
authors.forename: X G
authors.initials: XG
authors.lastname: Gong
authors.forename: J X
authors.initials: JX
authors.lastname: Zhong
authors.forename: R Q
authors.initials: RQ
authors.lastname: Wu