The vibronic ground state of HO–H–OH− represents axial Ra and Sa enantiomers, with equal probabilities. It can be prepared thermodynamically at low temperatures (4K). If the chirality is measured to be Ra, then wavefunction collapse induces periodic quantum stereo-mutation from Ra to Sa to Ra to Sa and so on. Similarly, the observation of Sa induces chirality flips from Sa to Ra to Sa to Ra and so on. The period of stereo-mutation is τ = 2.554 ps. The phenomenon is supported by the low energy barrier 174.6 hc cm−1 between the enantiomers and by the light masses of the hydrogen atoms, which interchange positions during stereo-mutation. Interchanges of heavier atoms and higher energy barriers would prohibit Schrödinger cat ground states. This is demonstrated for the counter example, isotopically substituted 12CDH13CH2–Si–12C13C. The results are obtained by means of quantum chemical calculations and quantum dynamics simulations.