A theoretical study of the complexes between dihydrogen, H-2, and a series of amine, phosphine, and arsine derivatives (ZH(3) and ZH(2)X, with Z = N, P, or As and X = F, Cl, CN, or CH3) has been carried out using ab initio methods (MP2/aug-cc-pVTZ). Three energetic minima configurations have been characterized for each case with the H-2 molecule in the proximity of the pnictogen atom (Z). In configuration A, the a-electrons of H-2 interact with sigma-hole region of the pnictogen atom generated by the of X-Z bond. These complexes can be ascribed as pnictogen bonded. In configuration C, the lone electron pair of Z acts as the Lewis base, and H-2 plays the role of the Lewis acid. Finally, configuration B presents a variety of noncovalent interactions depending on the binary complex considered. The atoms-in-molecules theory (AIM), natural bond orbitals (NBO) method as well as the density functional theory-symmetry adapted perturbation theory (DFT-SAPT) approach were used in this study to deepen the nature of the interactions considered.