The Acknowledgements section should read as follows: “We are grateful to Olaf Leupold, Ilya Sergeev, and Hans Christian Wille for the preparation of the NFS experiment and for assistance with the measurement of NFS spectra at the P01 beamline of the PETRA-III synchrotron (DESY, Hamburg, Germany); to Konstantin Glazyrin and Anna Pakhomova for assistance with the synthesis of poly hydrides in the laser heating device and with the measure ment of X‑ray diffraction patterns at the P02 beamline of the PETRA-III synchrotron (DESY, Hamburg, Germany); and to Piter Liermann for assistance with the measurement of the pressure at the Raman setup at the P02 beamline of the PETRA-III synchrotron (DESY, Hamburg, Germany). We acknowledge the European Synchrotron Radiation Facility for provision of synchrotron radiation facilities and we would like to thank M. Mezouar and V. Svitlyk for assistance in using beamline ID27”.