Ab-initio quantum mechanical calculation is used to calculate the N-14 and H-2 nuclear quadrupole resonance (NQR) parameters (eta and chi) of CH3N2+ ion and the ion shellvated by H-2 molecules [CH3N2+(H-2)(n=1-9)]. On the basis of NQR parameters, three distinct shells (A, B and C) were identified. To obtain these data we had to evaluate the electric field gradient (EFG) around any atom in each situation. EFG's were calculated by the GAUSSIAN 98 program using the MP2/6-311G** method. (C) 2002 Elsevier Science B.V. All rights reserved.