▎ 摘　　要

Single-wall carbon nanotube bundles (SWCNTBs) undergo structural phase transformations under pressure. Examination of the electronic band structure reveals that bundles of SWCNTs with three-fold symmetry have increased quasi band gaps, while bundles of SWCNTs without three-fold symmetry remain metallic under hydrostatic compression. (C) 2002 Elsevier Science B.V. All rights reserved.