Projector augmented plane wave

In this review, I have interpreted the term Car-Parrinello methods in the broad sense to mean those which combine first-principles quantum mechanical methods with molecular dynamics methods. I use this term synonymously with uh initio molecular dynamics, first-principles molecular dynamics, and ab initio simulations. Thus, ways of solving the many-body electronic problem, such as Hartree-Fock and correlation methods, are included, in addition to the projector-augmented plane-wave method. In the original Car-Parrinello method, molecular motion is treated classically via... 

We now discuss the most important theoretical methods developed thus far the augmented plane wave (APW) and the Korringa-Kolm-Rostoker (KKR) methods, as well as the linear methods (linear APW (LAPW), the linear miiflfm-tin orbital [LMTO] and the projector-augmented wave [PAW]) methods. 

Gaussian and Augmented Plane Waves Method with the Gaussian-t3rpe projectors... 

Floizwarth N A W, Matthews G E, Dunning R B, Tackett A R and Zeng Y 1997 Comparison of the projector augmented-wave, pseudopotential and linearized augmented-plane-wave formalisms for density-functional calculations of solids Phys. Rev. B 55 2005... 

The projector augmented-wave (PAW) DFT method was invented by Blochl to generalize both the pseudopotential and the LAPW DFT teclmiques [M]- PAW, however, provides all-electron one-particle wavefiinctions not accessible with the pseudopotential approach. The central idea of the PAW is to express the all-electron quantities in tenns of a pseudo-wavefiinction (easily expanded in plane waves) tenn that describes mterstitial contributions well, and one-centre corrections expanded in tenns of atom-centred fiinctions, that allow for the recovery of the all-electron quantities. The LAPW method is a special case of the PAW method and the pseudopotential fonnalism is obtained by an approximation. Comparisons of the PAW method to other all-electron methods show an accuracy similar to the FLAPW results and an efficiency comparable to plane wave pseudopotential calculations [, ]. PAW is also fonnulated to carry out DFT dynamics, where the forces on nuclei and wavefiinctions are calculated from the PAW wavefiinctions. (Another all-electron DFT molecular dynamics teclmique using a mixed-basis approach is applied in [84].)... 

Most plane wave calculations use ultrasoft pseudopotentials (USPP),15,28 which describe the core electrons of atoms in a mathematically efficient form that greatly reduces the computational cost associated with heavy atoms. An increasing number of calculations used the projector augmented wave (PAW) approach instead.28 In most circumstances where both approaches can be used, the differences between USPP and PAW calculations are minor. Some exceptions to this observation include transition metals with large magnetic moments (e.g., Fe) and alkali metals.28... 

The partitioning of the density introduced in (14) is borrowed from the projector augmented-wave approach [5]. Its special form separates the smooth contributions n, characteristic of the interatomic regions, from the quickly varying terms close to the atoms n.4. ua is a smooth local term which compensates for the overlap of the soft and the hard densities in the atomic region, so that the integrals can still be expanded over all space. In our current implementation the densities h r),nA r), and h-A(r) are expanded in plane-waves and products of primitive Gaussians centered on atom A, respectively... 

Many periodic codes are mentioned in the literature, mostly based on either a plane waves basis set and pseudopotentials or projector-augmented waves. Some of this software can be purchased, and the rest is available through collaboration with the main development team or downloadable... 

A Projector Augmented Wave (PAW) Code for Electronic Structure Calculations, Part 11 Pwpaw for Periodic Solids in a Plane Wave Basis. 

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