Raman phonon spectra and lattice dynamics of 9,10-dinitroanthracene under pressure

Raman phonon spectra of 9,10-dinitroanthracene have been recorded in the pr essure range 0-6GPa. No phase transition is detected up to the maximum pres sure studied. Quasi Harmonic Lattice Dynamics calculations, based on an ato m-atom potential previously modeled on homologous 9,10-disubstituted anthra cenes, have been performed. The optimized potential was used to calculate t he equilibrium geometry and the lattice phonon frequencies as a function of pressure. The calculated structure at ambient conditions closely resembles the experimental one. The calculated phonon frequencies show a good agreem ent with the experimental values at all pressures measured.