In this work we present a ¿rst-principles density functional study of the vibrational properties of ZnAl2 O4 and ZnGa2 O4 as function of hydrostatic pressure. Based on our previous structural characterization of these two compounds under pressure, herewith, we report the pressure dependence on both systems of the vibrational modes for the cubic spinel structure, for the CaFe2 O4-type structure (Pnma) in ZnAl2 O4 and for marokite (Pbcm) ZnGa2 O4. Additionally we report a second order phase transition in ZnGa2 O4 from the marokite towards the CaTi2 O4-type structure (Cmcm), for which we also calculate the pressure dependence of the vibrational modes at the ¿ point. Our calculations are complemented with Raman scattering measurements up to 12 GPa that show a good overall agreement between our calculated and measured mode frequencies. ; CONACyT M'exico under the project J-59853-F, PROALMEX-DAAD-CONACYT, Spain and CGSTIC ¿ Cinvestav. S. L.-M ; MICINN MAT2007-65990-C03-03/01 ; MICINN MAT2010-21270-C04-01/03/04 ; MICINN CSD2007-00045 ; Manjón Herrera, FJ.; Lopez-moreno, S.; Rodríguez-hernández, P.; Muñoz, A.; Romero, AH.; Errandonea, D.; Rusu, E. (2011). Lattice dynamics of ZnAl2O4 and ZnGa2O4 under high pressure. ANNALEN DER PHYSIK. 523(1-2):157-167. doi:10.1002/andp.201000096. ; Senia ; 157 ; 167 ; 523 ; 1-2