Local

Towards user-intervention-free computation of material properties with Wannier functions

Dr Valerio Vitale

University of Cambridge

Monday 28th February 2019
Time: 12.00pm
Venue: Room G01, Royal School of Mines, Imperial College London
Contact: Ms Hafiza Bibi
Tel: 020 7594 7252

Abstract: Maximally localized Wannier functions (MLWFs) [1] have been playing an increasingly relevant role in the computation of many electronic, magnetic and transport properties of materials from first principles calculations [2]. Morover, being a localized basis makes them very actractive for highly-accurate beyond-DFT models, e.g. Hubbard models and DMFT [2].

In a recent paper by Damle, Lin and Ying, the authors describe the selected column of density matrix algorithm (SCDM) for obtaining localised Wannier functions in extended systems [3], which does not require any initial guess needed, at variance with the conventional approach [1]. The algorithm may be extended to the case of a set of bands that do not form an isolated manifold (i.e., are entangled), by introducing only two parameters [4].

We have implemented a fully-integrated framework that combines the AiiDA workflow [5], the Quantum ESPRESSO [6] program and the Wannier90 program [7] to automatically choose the free parameters in the SCDM method and therefore produce user-intervention-free MLWFs [8]. We have tested the method on a range of 1D-, 2D- and 3D-systems, leveraging the power of the AiiDA workflow for handling massively parallel calculations. This opens the way for high-throughput, user-intervention-free computation of advanced materials properties with Wannier functions. 

[1]  Phys. Rev. B 56 20 (1997)

[2]  Rev. Mod. Phys. 84 (2012) 

[3]  J. Comp. Phys. 334 (2017)

[4]  arXiv:1703.06958v1 (2017)

[5]  Comp. Mat. Sci. 111(Supplement C) (2016) 

[6]  J Phys. Cond Matt 29 46 (2017)

[7] Comp. Phys. Comm. 185 (2014) 

[8]  in preparation 

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