Structural, vibrational, and electronic properties of BaReH under pressure.

We present a study of the high-pressure behavior of BaReH, a novel hydrogen-rich compound, using optical, Raman, and infrared spectroscopy as well as synchrotron x-ray diffraction. The x-ray diffraction measurements demonstrate that BaReH retains its hexagonal structure on room temperature compression up to 40 GPa. Optical absorption shows the absence of a gap closure to 80 GPa.