  Capillary and van der Waals forces cause nanotubes to deform or even collapse
under metal contacts. Using ab-initio bandstructure calculations, we find that
these deformations reduce the bandgap by as much as 30\%, while fully collapsed
nanotubes become metallic. Moreover degeneracy lifting, due to the broken axial
symmetry and wavefunctions mismatch between the fully collapsed and the round
portions of a CNT, leads to a three times higher contact resistance. The latter
we demonstrate by contact resistance calculations within the tight-binding
approach.
