Vibrational properties of bulk crystalline barium halides BaCl${}_2$, BaBr${}_2$, and BaI${}_2$ are theoretically investigated for orthorhombic and hexagonal symmetry with ab initio methods in density functional theory. It is demonstrated that the used method is capable of predicting frequencies of vibrational modes, their symmetry types, and corresponding Raman intensities in reasonable agreement with experimental data for orthorhombic and hexagonal BaCl${}_2$ and BaBr${}_2$ nanocrystals embedded in fluorozirconate glasses. For orthorhombic BaCl${}_2$, a Raman-active phonon mode could be predicted theoretically that was not observed in measurements before.

• Received 28 September 2010
• Corrected 14 February 2011

DOI:https://doi.org/10.1103/PhysRevB.83.024107