This Letter is prepared to reply the comment by Stace et al. [A.J. Stace, N.R. Walker, R.R. Wright, S. Firth, Chem. Phys. Lett. 329 (2000) 173-175] on our Letter in Chemical Physics Letters [A.M. El-Nahas, N. Tajima, K. Hirao, Chem. Phys. Lett. 318 (2000) 333]. The authors performed new experiments and showed the presence of clear peaks with the same m/z values as the ions of interest. They assigned these peaks to fragmentation of impurities and not to the decomposition products of the Cu2+ systems. It is recommended that the experimental determination of the desired products be repealed. Our calculations have been performed at high ab initio level of theory and this provides strong evidence for the stability of di-ligated Cu2+ complexes with water and ammonia and proposes the possibility of detecting one-ligand systems.