Density functional theoretic (DFT) calculations have been carried out for B-2@C-60, O-2@C-60 and Ge-2@C-60 to study the influence of confinement on the relative stability between the singlet and the triplet states of paramagnetic diatomic molecules B-2, O-2 and Ge-2. Although the energy gap between the respective singlet and triplet states of B-2 and O-2 remains unaltered on encapsulation inside the C-60 cage, the relative stability of the singlet and triplet states of the complex Ge-2@C-60 varies with the orientation of Ge-2 inside the cage. Unlike that of B-2 and O-2, the bond length of Ge-2 is reduced significantly inside the cage. (C) 2014 Elsevier B.V. All rights reserved.