A mixed ultrasoft/normconserved pseudopotential scheme

Mixed ultrasoft/norm-conserved pseudopotential scheme.

Electronic polarization in the ultrasoft pseudopotential formalism

An expression is given for the electronic polarization of an insulating crystal within the ultrasoft pseudopotential scheme. The pseudopotential charge-augmentation terms modify the usual Berry-phase expression, and also give rise to a second term that takes the form of a conventional expectation value.

Quasiatomic orbitals for ab initio tight-binding analysis

Wave functions obtained from plane-wave density-functional theory (DFT) calculations using normconserving pseudopotential, ultrasoft pseudopotential, or projector augmented-wave method are efficiently and robustly transformed into a set of spatially localized nonorthogonal quasiatomic orbitals (QOs) with pseudoangular momentum quantum numbers. We demonstrate that these minimal-basis orbitals ca...

Ultrasoft spin-dependent pseudopotentials.

The use of the spin-dependent pseudopotentials has been shown to markedly enhance the transferability of the commonly used spin-neutral pseudopotential method for the study of the structural and magnetic properties of transition-metal-containing materials. Unfortunately, because the method was based on the rather expensive norm-conserving pseudopotential formalism, the method was limited to the...

Virtual crystal approximation revisited: Application to dielectric and piezoelectric properties of perovskites

We present an approach to the implementation of the virtual crystal approximation ~VCA! for the study of properties of solid solutions in the context of density-functional methods. Our approach can easily be applied to any type of pseudopotential, and also has the advantage that it can be used to obtain estimates of the atomic forces that would arise if the real atoms were present, thus giving ...