Can hydrogen be stored inside carbon nanotubes under pressure in   gigapascal range?
  By using a newly fitted multi-parameter potential to describe the van der Waals interaction between carbon and molecular hydrogen, we study the hydrogen storage inside carbon nanotubes (CNT's) under pressure in gigapascal range. Comparing with the results of graphite, we find that the shape change of the nanotubes (the curvature effect) provides a different storage mechanism for hydrogen. The negative free energy change for hydrogen storage inside CNT's makes it possible to use CNT's as the nanocontainer [Carbon 45, 315 (2007)]. 
X. H. Zhang, X. G. Gong, Z. F. Liu