Comparison of IR messenger spectra of proton-bound water dimer H5O2+ tagged with He, Ne and Ar. Reprinted with permission from Johnson, C.J., Wolk, A.B., Fournier, J.A., Sullivan, E.N., Weddle, G.H., Johnson, M.A.: Communication: He-Tagged Vibrational Spectra of the SarGlyH+ and H+(H2O)2,3 Ions: Quantifying Tag Effects in Cryogenic Ion Vibrational Predissocation (CIVP) Spectroscopy. J Chem Phys. 140, 22 (2014). Copyright 2014, AIP Publishing LLC.