We revealed the arrangement of single wall carbon nanotube (SWNT) which is suitable for the adsorption of hydrogen by means of grand canonical Monte Carlo (GCMC) simulation with simple cylindrical model Here, we calculated the amount of adsorbed hydrogen with triangular lattice (TL) and square lattice (SL) model for the bundle structure with venous kinds of tube diameters (D) and inter axis distances (R(a)) Our results indicate that any arrangements having smaller R(a) are not suitable for the storage of hydrogen and the adsorption amount of hydrogen can be achieved the target value (6 wt % and 45 kg m(-3)) proposed by Department of Energy (DOE) in United States by SWNTs having larger R(a) at 77 K and 1 MPa Furthermore these results show that the best arrangement of SWNTs for the adsorption of hydrogen at this condition is TL structure having R(a) = 2 159 nm and D = 1 227 nm (C) 2010 Professor T Nejat Veziroglu Published by Elsevier Ltd All rights reserved