Real Space Orthogonal Projector-Augmented-Wave Method

TL;DR

This paper introduces an orthogonal version of the PAW method, called OPAW, which improves computational efficiency and can be integrated with various electronic structure theories, accurately reproducing band gaps for solids.

Contribution

The paper presents a novel orthogonalization transformation for the PAW method, enhancing its efficiency and compatibility with other electronic structure approaches.

Findings

OPAW reproduces band gaps accurately for various solids.

OPAW combines orthogonality with large grid spacings and small spectral ranges.

The method is computationally inexpensive and versatile.

Abstract

The projector augmented wave (PAW) method of Bl\"ochl makes smooth but non-orthogonal orbitals. Here we show how to make PAW orthogonal, using a cheap transformation of the wave-functions. We show that the resulting Orthogonal PAW (OPAW), applied for DFT, reproduces (for a large variety of solids) band gaps from the ABINIT package. OPAW combines the underlying orthogonality of norm-conserving potentials with the large grid spacings and small spectral range in PAW. The OPAW framework can also be combined with other electronic structure theory methods.