Density Functional Perturbation Theory to Predict Piezoelectric Properties

Among the various computational methods in materials science, only first-principles cal- culation based on the density functional theory has predictability for unknown material. Especially, density functional perturbation theory (DFPT) can effectively calculate the second derivative of the total energy with respect to the atomic displacement. By using DFPT method, we can predict piezoelectric constants, dielectric constants, elastic con - stants, and phonon dispersion relationship of any given crystal structure. Recently, we established the computational technique to decompose piezoelectric constants into each atomic contribution, which enable us to gain deeper insights to understand the piezo electricity of material. Therefore, in this chapter, we will introduce the computational framework to predict piezoelectric properties of polar material by means of DFPT and details of decomposition technique of piezoelectric constants. Then, we will show some case studies to predict and discover new piezoelectric material.