The reorganization energy of donor and acceptor moieties in molecular complexes of the Group IIIA element halides with the Group V element hydrides are obtained from ab initio and density functional theory calculations, and the correction energy related to the basis set superposition error (BSSE) is calculated by the balance function method. The reorganization energy gives a positive contribution to the donor-acceptor bonding energy, and BSSE correction gives a negative contribution, so they partially cancel each other out. For acceptors, the reorganization energy ranges within 15-35 kJ/mol, while for donors, it varies from 0.2 (NH₃) to 9 kJ/mol (AsH₃). The BSSE correction is shown to be important for small basis sets without polarization functions. The absolute value of the BSSE energy correction decreases in the NH₃ > PH₃ > AsH₃ series and correlates with the variation in the dissociation energy of complexes. The donor-acceptor bonding energy of these complexes is 20-30 kJ/mol larger on average than the calculated dissociation enthalpy of complexes in the gas phase.