Lattice dynamics and phase transition of acetylene

Abstract

The statical properties and lattice dynamics of the two known phases of crystalline acetylene have been studied, using a model which takes account of electrostatical intermolecular as well as atom-atom interactions. Good agreement with observed statical and dynamical properties of both phases has been achieved. The calculated phonon dispersion curves and group symmetry considerations led us to the identification of the phonons in both phases which are possibly associated with the structural phase transition.