FIRST-PRINCIPLES STUDY OF PIEZOELECTRICITY IN PBTIO3

The first self-consistent computations of piezoelectricity in a ferroe lectric are presented. spontaneous polarization, dynamical charges (Z ), and the full piezoelectric stress tensor of PbTiO3 were determined from ground-state Berry's phase calculations using the all-electron li nearized augmented plane wave method. Both the proper and total piezoe lectric moduli were computed and were found to be significantly differ ent. The theoretical piezoelectric stress moduli, e(15) = 3.15 C/m(2), e(31) = -0.93 C/m(2), and e(33) = 3.23 C/m(2), agree well with single crystal experimental data.