The changes in the structure and bonding of the hydrogen bonded complexes between hydrogen halides and ammonia, phosphine and water, when the hydrogen halides form beryllium bonds with BeCl2 have been investigated by CCSD(T)/aug-cc-pVTZ ab initio calculations. Although the experimental evidence showed that a spontaneous proton transfer (PT) from hydrogen halides toward ammonia does not occur, and only is observed for HI when interacting with trimethylamine, we have found that a spontaneous PT does occur when the halide forms beryllium bonds with BeCl2. The complexes so formed are the result of the interaction of Cl2BeX- with NH4+, PH4+, H3O+, respectively. (C) 2013 Elsevier B. V. All rights reserved.