Isotope effect in a Cu-H(D) system with hexagonal hydride phase

The decomposition pressure pdec of copper deuteride has been experimentally determined in a diamond anvil cell. The value of 6.8±0.6  GPa is lower than the corresponding pressure of copper hydride. The difference between standard Gibbs energies of decomposition of copper hydride and deuteride has been calculated as equal to − 5.2 kJ mol−1 (H2). The zero-point energy of hydrogen vibration in the hydride lattice has been obtained applying the localized harmonic oscillator model.