First-principles study of the multi-mode anti-ferroelectric transition   of PbZrO3
  We have studied ab initio the phase transition in PbZrO3, a perovskite oxide usually presented as the prototypic anti-ferroelectric material. Our work reveals the crucial role that anti-ferrodistortive modes -- involving concerted rotations of the oxygen octahedra in the structure -- play in the transformation, as they select the observed anti-ferroelectric phase, among competing structural variants, via a cooperative trilinear coupling. 
Jorge Iniguez (ICMAB-CSIC), Massimiliano Stengel (ICREA and   ICMAB-CSIC), Sergey Prosandeev and L. Bellaiche (University of...
cond-mat.mtrl-sci