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Liebman, J.F.; Romm, M.J.; Meot-Ner (Mautner), M.; Cybulski, S.M.; Scheiner, S., Isotropy in ionic interactions. 2. How spherical is the ammonium ion? Comparison of the gas-phase clustering energies and condensed-phase thermochemistry of K+ and NH4+, J. Phys. Chem., 1991, 95, 3, 1112, https://doi.org/10.1021/j100156a018 . [all data]