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F. Libisch, M. Marsman, K. Yu, G. Kresse, E Carter:
"Embedding approaches for bulk systems using projector-augmented waves";
Vortrag: 9th congress of the International Society for Theoretical Chemical Physics (ISTCP IX), Grand Forks, North Dakota, USA (eingeladen); 17.07.2016 - 22.07.2016.

Density-functional embedding allows for combining different levels of theory in one
calculation (for a review see [1]). Consider, for example, dissociative adsorption of gas
molecules on metal surfaces: the extended metal surfaces can be accurately treated by
periodic density functional theory approaches, while charge transfer processes at the
adsorption site require more accurate correlated wave function (CW) approaches. The
latter, in turn, scale unfavourably with system size, and thus do not allow for treating
more than approximately fifteen heavy atoms. Instead, we separate the problem into a
cluster of interest and the surrounding metal surface. Their interaction is mediated by a
scalar embedding potential determined at the DFT level. The cluster can now efficiently
be treated by CW techniques, in the presence of the embedding potential.
We have recently extended our approach [2] to the popular VASP software package,
including the projector-augmented wave (PAW) formalism [3]. This allows for treating
much larger unit cells at higher accuracy, and to exploit the full framework of VASP: the
PAW formalism (i) offers an exact transformation between the original, oscillating wave
function and the pseudized, slowly varying pseudo wave function used in the
computation and (ii) explicitly treats the all-electron wave functions, albeit within the
frozen-core approximation. We show that PAW-based density-functional embedding
yields robust, accurate embedding potentials, and discuss application cases and future
extensions based on a set of mutually orthogonal orbitals [4].
[1] F. Libisch, C. Huang, and E. A. Carter, Acc. Chem. Research, 47, 2768 (2014).
[2] K. Yu, F. Libisch, and E. A. Carter, J. Chem. Phys. 143, 102806 (2015).
[3] G. Kresse, and D. Joubert, Phys. Rev. B, 59, 1758, (1999)
[4] F. Manby, M. Stella, J. D. Goodpaster, and T. F. Miller Chem. Theory Comput., 8,
2564-2568 (2012).

http://publik.tuwien.ac.at/files/publik_253090.pdf