Lattice dynamics and elastic properties of PbF2 and BaF2 from quantum mechanical calculationsA. Dubinin, B. Winkler, K. Knorr and V. MilmanEur. Phys. J. B, 39 1 (2004) 27-33DOI: https://doi.org/10.1140/epjb/e2004-00166-1