Applications of the generalized gradient approximation to ferroelectric perovskites

Abstract

The Perdew-Burke-Ernzerhof generalized gradient approximation to the density functional theory is tested with respect to sensitivity to the choice of the value of the parameter $\kappa$, which is associated to the degree of localization of the exchange-correlation hole. A study of structural and dynamical properties of four selected ferroelectric perovskites is presented. The originally proposed value of $\kappa$=0.804 %(best suited for atoms and molecules) works well for some solids, whereas for the ABO${}_3$ perovskites it must be decreased in order to predict equilibrium lattice parameters in good agreement with experiments. The effects on the structural instabilities and zone center phonon modes are examined. The need of varying $\kappa$ from one system to another reflects the fact that the localization of the exchange-correlation hole is system dependent, and the sensitivity of the structural properties to its actual value illustrates the necessity of finding a universal function for $\kappa$.

15 pages, 2 figures, PRB in press

Cited by in corpus (6)

• Hybrid exchange-correlation functional for accurate prediction of the electronic and structural properties of ferroelectric oxides
• Energetics and Dipole Moment of Transition Metal Monoxides by Quantum Monte Carlo
• Atomistic simulations of the incipient ferroelectric KTaO${}_3$
• Quantitative analysis of the first-principles effective-Hamiltonian approach to ferroelectric perovskites
• Electronic structure of Co_xTiSe_2 and Cr_xTiSe_2
• Relative phase stability and lattice dynamics of NaNbO${}_3$ from first-principles calculations