Single-crystal vibrational spectrum of phenakite, Be2SiO4, and its interpretation using a transferable empirical force field

Using an oriented single crystal, Raman and infrared vibrational spectra have been measured for phenakite, Be2SiO4. The results have been interpreted on the grounds of Born-von Karman rigid-ion lattice-dynamical calculations, using empirical potentials derived from fitting the vibrational frequencies of a group of silicates, carbonates, and oxides, not including the substance under study. The very good agreement of our calculations with experimental data of independent origin and nature confirms the transferability of empirical potentials, and also their advantageous use for interpreting and reproducing the vibrational spectra of silicates and oxides in general.