The nature of the newly discovered intramolecular hydrogen-hydrogen interaction in iridium complexes (Ir-H ... H-N) was studied using the extended Huckel method. Consistent with experimental results, the interaction is found to be weakly attractive. Electrostatic interactions probably contribute significantly to this bonding mode. This hydrogen-hydrogen interaction might also be realized intermolecularly; restricted Hartree-Fock (RHF)/6-31G* computation yields an H ... H interaction energy of 9.29 kcal/mol in FH ... HLi.