You mean, in a chemical structure file? Create a unit cell that can be propagated periodically. Then load it with whatever you prefer: excel, calc, python, shell script... and perform the propagation along the desired tube axis.
If it's something more sophisticated (or even experimental) you had in mind, please specify.
Thank you for your response sir. I have the unit cell but I could make a surface using it. How can I create a nanotube? As there would be vacuum region at the center along axis? How would I design it's type (whether Type of nanotube--armchair, zigzag, chiral)? If you feel answer is elaborate, Please mention some references. Jürgen Weippert
An inorganic nanotube is a cylindrical molecule often composed of metal oxides.Inorganic nano-tubes are morphologically similar to carbon nanotubes and are observed in some mineral deposits of natural origin.Ceramics like titanium dioxide (TiO2), zirconium dioxide (ZrO2) and zinc oxide (ZnO) also form inorganic nanotubes.[