Pressure and temperature effects in lattice dynamics: 1,4-dibromonaphthalene

Raman phonon spectra of the quasi-linear crystal 1,4-dibromonaphthalene (DB rN) have been recorded as a function of temperature (ambient pressure) and in the pressure range 0-12.5 GPa at room temperature. No phase transition h as been detected up to the maximum pressure studied. Quasi-harmonic lattice dynamics calculations, based on intermolecular atom-atom potentials, repro duce well the ambient p, T crystal structure and the pressure and temperatu re dependence of the Raman-active lattice phonons. The high stability to pr essure of the quasi-one-dimensional molecular packing of DBrN is semi-empir ically rationalized by comparison to similar systems undergoing pressure-in duced phase transitions. (C) 2000 Elsevier Science B.V. All rights reserved .