Comment on: "Relativistic all-electron Hartree-Fock-Dirac calculation of aquasi one-dimensional chain of selenium atoms"

Hu et al. [Chem. Phys. Lett. 293 (1998) 277] reported results of a theoreti cal study of relativistic effects on the band structures of a Linear chain of selenium atoms. We argue here that their results are erroneous, i.e., th at their reported bandwidths are much too small and that the system is meta llic and not semiconducting. Furthermore, we shall argue that the linear ch ain is not a good approximation to the true helical structure of selenium c hains. Finally, we suggest that the relativistic effects of the Se chain ar e so small that this system is not a good one for studying such effects. (C ) 2000 Elsevier Science B.V. All rights reserved.