Extended Data Fig. 6: Rotational degrees of freedom in Cmca-12.
In panel a, we report the fit of the DFT-BLYP energy landscape for the rotation of one H2 molecule inside the Cmca-12 structure at 350 GPa. The intramolecular H2 potential is fitted with a Morse function in panel b. In panel c, we report the probability distribution of the reduced coordinate in the center-of-mass frame solved with the implicitly-restarted Lanczos algorithm (ground state and first excited states). Axes are in Bohr. The difference between the SSCHA ZPE and the exact ground-state as a function of the amplitude of the angular potential modulation is reported in panel d. The dashed line represent the value of the fit in panel a.
