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Partly occupied Wannier functions: Construction and applications

K. S. Thygesen·L. B. Hansen·K. W. Jacobsen
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Abstract

We have developed a practical scheme to construct partly occupied, maximally localized Wannier functions (WFs) for a wide range of systems. We explain and demonstrate how the inclusion of selected unoccupied states in the definition of the WFs can improve both their localization and symmetry properties. A systematic selection of the relevant unoccupied states is achieved by minimizing the spread of the resulting WFs. The method is applied to a silicon cluster, a copper crystal, and a Cu(100) surface with nitrogen adsorbed. In all cases we demonstrate the existence of a set of WFs with particularly good localization and symmetry properties, and we show that this set of WFs is characterized by a maximal average localization.

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K. S. Thygesen, L. B. Hansen, K. W. Jacobsen. 2005-06-20. Partly occupied Wannier functions: Construction and applications. https://doi.org/10.1103/physrevb.72.125119

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