Static compression of LiH to 250 GPa

The equation of state of LiH was extended to 252 GPa (V/V-0 = 32%) at room temperature using x-ray diffraction in diamond-anvil cells. LiH was shown to remain in the the NaCl (B1) structure under these conditions, and the predicted B1-B2 phase transition well known in neighboring alkali halides was not observed. Raman spectroscopy performed up to 120 GPa revealed all transverse and acoustic phonon modes at the X point of reciprocal space. The structural, equation of state and thermodynamic properties clarified in this study enable the benchmarking of current theoretical models.