## Automated high-throughput Wannierisation, a successful collaboration between E-CAM and the MaX Centre of Excellence

Maximally-localised Wannier functions (MLWFs) are routinely used to compute from first- principles advanced materials properties that require very dense Brillouin zone (BZ) integration and to build accurate tight-binding models for scale-bridging simulations. At the same time, high-thoughput (HT) computational materials design is an emergent field that promises to accelerate the reliable and cost-effective design and optimisation of new materials with target properties. The use of MLWFs in HT workflows has been hampered by the fact that generating MLWFs automatically and robustly without any user intervention and for arbitrary materials is, in general, very challenging. We address this problem directly by proposing a procedure for automatically generating MLWFs for HT frameworks. Our approach is based on the selected columns of the density matrix method (SCDM, see SCDM Wannier Functions) and is implemented in an AiiDA workflow.

### Purpose of the module

Create a fully-automated protocol based on the SCDM algorithm for the construction of MLWFs, in which the two free parameters are determined automatically (in our HT approach the dimensionality of the disentangled space is fixed by the total number of states used to generate the pseudopotentials in the DFT calculations).

A paper describing the work is available at https://arxiv.org/abs/1909.00433, where this approach was applied to a dataset of 200 bulk crystalline materials that span a wide structural and chemical space.

### Background information

This module is a collaboration between E-CAM and the MaX Centre of Excellence.

In the SCDM Wannier Functions module, E-CAM has implemented the SCDM algorithm in the *pw2wannier90.f90* interface code between the Quantum ESPRESSO software and the Wannier90 code. This implementation was used as the basis for a complete computational workflow for obtaining MLWFs and electronic properties based on Wannier interpolation of the BZ, starting only from the specification of the initial crystal structure. The workflow was implemented within the AiiDA materials informatics platform, and used to perform a HT study on a dataset of 200 materials, as described in here.

More information at https://e-cam.readthedocs.io/en/latest/Electronic-Structure-Modules/modules/W90_MaX_collab/readme.html