The electronic structure of single-walled carbon nanotube (SWNT) in the gro
wth is studied by using the first-principle discrete variable calculations.
I We find the electronic structure of the mouth is remarkably different fr
om that of the body due to dangling bonds. The corresponding valence electr
ons not only directly change the bonding model of the mouth, strengthen the
bonding between carbon atoms and induce carbon atoms shift to tube core al
ong the radial, which is in good agreement with the morphology of perfect t
ip observed in the experiments, but also reduce the chemical stability of c
arbon nanotube. The electronic structure differing from the closed carbon n
anotube determines the different operation behavior of carbon nanotube in t
he growth in the synthesis of nano-material.