Zero-temperature equation of state of quasi-one dimensional H2
  We have studied molecular hydrogen in a pure 1D geometry and inside a narrow carbon nanotube by means of the diffusion Monte Carlo method. The one-dimensionality of H2 in the nanotube is well maintained in a large density range, this system being closer to an ideal 1D fluid than liquid 4He in the same setup. H2 shares with 4He the existence of a stable liquid phase and a quasi-continuous liquid-solid transition at very high linear densities. 
M.C. Gordillo, J. Boronat and J. Casulleras