Raman scattering in YBa2Cu3O7: a comprehensive theoretical study in comparison with experiments

All Raman-active phonon modes of YBa2⁢Cu3⁢O7 are investigated by first-principles linearized augmented plane-wave calculations based on density-functional theory for a fully optimized crystal structure. The calculated frequencies as well as the Raman scattering intensities are in excellent agreement with measured Raman spectra. The effect of site-selective isotope substitution on the Raman spectra is investigated. The substitution not only shifts the phonon frequencies, but also leads to dramatic changes in the scattering intensities.