Wannier Developers 2023
Location: CECAM-UK-DARESBURY
Organisers
Please go to event webpage for information and to register.
Wannier90 is the most widely-used software for obtaining a Wannier representation of electronic structure calculations, providing a reference implementation--based on maximal localisation in real space of the Wannier functions--that has been widely adopted by the solid state/electronic structure community [1].
In addition to fundamental advantages in the study of electrical polarisation and other quantities which cannot be unambiguously defined in terms of Bloch states, Wannier functions provide an effective mechanism for extracting a subset of states from a system of many overlapping bands, whose real-space representations present an efficient way for interpolating band structures at arbitrary wave vectors. This last feature is of enormous benefit for the calculation of properties requiring a very fine sampling of the Brillouin zone, such a Berry curvature, since sufficient resolution is scarcely possible (or unnecessarily expensive) with self-consistent band structure codes.
Wannier90 is broadly used to provide Wannier functions as a starting point in calculation of complex materials properties with a variety of different open-source codes. These include electron-phonon calculations with EPW [2] or perturbo [3], topological properties using WannierTools [4] or Z2Pack [5], Berry phase properties using WannierBerri [6], tight-binding calculations, AiiDA integration (see [1]), among many others. These constitute an ecosystem of codes based on the output of Wannier90. Wannier90 itself effectively abstracts away the more technical issues of electronic structure calculations (basis sets, exchange correlation functional, etc), provides a common framework for different kinds of properties calculation, and is interfaced to the most widely-used electronic structure codes. This means that developments in Wannier90 and Wannier90-related post-processing codes become rapidly available to a very wide community of electronic structure researchers.
The wealth of activity based around Wannier90, and Wannier functions in general, highlights their usefulness in a wide range of basic and technologically interesting areas, such as topological properties of matter, and it is reasonable to expect Wannier-based methods to become increasingly important in the future. Interesting developments in the core Wannier90 code that are expected to feature in the 2023 meeting include CCP9's parallel library implementation, further integration with the electronic structure library (ESL) project, interfaces to more electronic structure codes and additional functionality relating to symmetrisation of Wannier functions.
The 2023 developer meeting will encompass the wider ecosystem of Wannier-related activity, with representatives of many different code projects expected to participate, and intends to foster collaboration, knowledge exchange and community building among the different code projects and activities.
[1]: Giovanni Pizzi et al, J. Phys.: Condens. Matter 32 165902 (2020)
[2]: Samuel Poncé et al, Comput. Phys. Commun. 209 116--133 (2009)
[3]: Jin-Jian Zhou et al, Comput. Phys. Commun. 264, 107970 (2021)
[4]: QuanSheng Wu et al, Comput. Phys. Commun. 224, 405 (2018)
[5]: Dominik Gresch et al, Phys. Rev. B 95, 075146 (2017)
[6]: Stepan S Tsirkin npj Comput Mater 7, 33 (2021)
References
Jae-Mo Lihm (Seoul National University) - Organiser
United Kingdom
Jerome Jackson (STFC Daresbury Laboratory) - Organiser
Arash Mostofi (Imperial College London) - Organiser
Jonathan Yates (University of Oxford) - Organiser
United States
Sophie Beck (Flatiron Institute) - Organiser
Jennifer Coulter (Harvard University) - Organiser