The possibility of encapsulation of one and two H-2 molecule inside C-50 fullerene was investigated at MP2 level of theory. By calculating the complexation energy, it was confirmed that H-2@C-50 complex is thermodynamically stable, while 2H(2)@C-50 one is unstable. This was evidenced by negative complexation energy for H-2@C-50 and positive one for 2H(2)@C-50 calculated using different basis sets. Examination of the host-guest interaction forces and strain energies in both complexes and the maximum expansion of the C-50 cage before C-C bonds breaking also proved that only one H-2 can reside inside the C-50 cage. (C) 2014 Elsevier B. V. All rights reserved.