From plane waves to local Gaussians for the simulation of correlated periodic systems

George H. Booth,1, a) Theodoros Tsatsoulis,2 Garnet Kin-Lic Chan,3 and Andreas Gr¨uneis2, b)


1)Department of Physics, King’s College London, Strand, London, WC2R 2LS, UK

2)Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany

3)Department of Chemistry, Frick Laboratory, Princeton University, Princeton, New Jersey 08544, USA

Abstract

We present a simple, robust and black-box approach to the implementation and use of local, periodic, atomcentered Gaussian basis functions within a plane wave code, in a computationally efficient manner. The procedure outlined is based on the representation of the Gaussians within a finite bandwidth by their underlying plane wave coefficients. The core region is handled within the projected augment wave framework, by pseudizing the Gaussian functions within a cut-off radius around each nucleus, smoothing the functions so that they are faithfully represented by a plane wave basis with only moderate kinetic energy cutoff. To mitigate the effects of the basis set superposition error and incompleteness at the mean-field level introduced by the Gaussian basis, we also propose a hybrid approach, whereby the complete occupied space is first converged within a large plane wave basis, and the Gaussian basis used to construct a complementary virtual space for the application of correlated methods. We demonstrate that these pseudized Gaussians yield compact and systematically improvable spaces with an accuracy comparable to their non-pseudized Gaussian counterparts. A key advantage of the described method is its ability to efficiently capture and describe electronic correlation effects of weakly bound and low-dimensional systems, where plane waves are not sufficiently compact or able to be truncated without unphysical artifacts. We investigate the accuracy of the pseudized Gaussians for the water dimer interaction, neon solid and water adsorption on a LiH surface, at the level of second-order Møller–Plesset perturbation theory.

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https://arxiv.org/pdf/1603.06457.pdf