A computational study at various levels of theory was undertaken for protonated NCX (X = F, Cl, Br) complexes, which were previously characterized using the MP216-311++G(d,p) procedure. It is shown that the apparent destabilization of the halogen bond in some of these complexes is due to a basis set deficiency. The protonated species were re-optimized at MP216-311++G(2df,2pd) and found to be more strongly bound than their unprotonated counterparts. These new results suggest that only H+NCF center dot center dot center dot F may be considered to be destabilized, since no local minimum was found. (C) 2015 Elsevier B.V. All rights reserved.