Electronic structure and dimerization of a single monatomic gold wire

The electronic structure of a single monatomic gold wire has been calculate d with density-functional calculations taking into account relativistic eff ects. For stretched structures in the experimentally accessible range the c onduction band is exactly half-filled, whereas the band structures are more complex for the optimized structure. Moreover, for these structures the sy stem can lower its total energy by letting the bond lengths alternate leadi ng to more or less separated dimers with bond lengths of about 2.5 Angstrom , largely independent of the stretching. Finally, finite Au-2, Au-4, and Au -6 chains possess electronic properties very similar to those of the infini te chain. (C) 2000 Elsevier Science B.V. All rights reserved.