Dynamics of antiferroelectric phase transition in PbZrO3

The dynamics of the phase transition in antiferroelectric ${\mathrm{PbZrO}}_{3}$ which is the subject of a decades-long debate, is examined using first-principles-based simulations. This is achieved through the development of a computational approach that allows calculations of generalized complex susceptibilities at an arbitrary point of the Brillouin zone. Application of this approach to the case of ${\mathrm{PbZrO}}_{3}$ predicts the temperature evolution of many of its lattice modes, some of which remain elusive or even ``invisible'' in experiments. The computational data suggest that two lattice modes are primarily responsible for the antiferroelectric phase transition in this material: the one associated with oxygen octahedra tilts dynamics and the other due to lead ions antipolar vibrations.