[ase-users] structure.py: adding hydrogens to nanotubes and circumventing m<n

[Alex Eftimiades]

	I am looking to simulate some transport properties of carbon  
nanotubes, but I need to be able to selectively add hydrogens on one  
edge of the nanotube (as you can do with the graphene 'saturated'  
option.) I understand that is a rather obscure feature, though I would  
argue that being able to add hydrogens on to both sides of the  
nanotube is quite reasonable (as this is often happens in practice.)  
Also, switching n<==>m changes the handedness (i.e. +/- sign of the  
chirality) of the nanotube, so forcing m<n is actually a limiting  
condition that I need to circumvent for my research.

	Could anyone give me a recommendation as to how I might modify the  
structure.py file to add these options?

Thanks
Alex