First-principles theory of structural phase transitions in cubic perovskites

A review is given of recent developments in which first-principles electronic-structure calculations have been used to determine, with chemical specificity, the structural properties of cubic perovskite materials. Direct application of these methods can be used to determine the ground-state (zero-temperature) distorted structure, the lattice vibrational properties in harmonic and anharmonic order, and dielectric properties such as Born effective charges and piezoelectric constants. By the indirect construction of model effective Hamiltonians and the fitting of these to the first-principles results, one can obtain (in most cases) the correct sequence of ferroelectric and/or antiferrodistortive structural phase transitions, with predicted transition temperatures typically within 30% of the experimental ones. Prospects for the application of these approaches to solid-solution ferroelectrics, to the study of finite-temperature piezoelectric properties, and to ferroelectrics in confined geometries, are briefly discussed.