High-level electronic-structure calculations of novel materials with the all-electron code exciting

First-principles codes of computational materials science can predict a variety of material properties, as evidenced in numerous publications and public databases [1,2]. In this community, various methods are used that may rely on certain approximations. Furthermore, the users of these codes can control the numerical precision by choosing appropriate computational parameters. In order to know, however, what is ultimately needed to reach a certain precision, users have to converge their system of interest by varying all the relevant input parameters. This is not only a tedious process, but also consumes substantial computational resources.

To help reducing such efforts in the future and to guide users in their choice of methods, approximations, and computational parameters, we aim at developing a recommender system for users of electronic-structure codes. For this purpose, reliable benchmark data are needed. One such benchmark dataset is in the focus of this project. It concerns a set of 10 semiconducting materials, consisting of 4-8 atoms in the unit cell. They have been chosen as good examples in view of system size and composition, but also because they are promising candidates for applications in optoelectronic devices.
 

The goal is to systematically converge their electronic structure until the respective band gap has reached a certain level of numerical precision. The method of choice here is the so-called GW approximation of many-body perturbation theory, starting from density-functional-theory (DFT) results. This method is considered the state-of-the-art for computing the electronic structure of materials. The electronic-structure code to be employed in this project is "exciting" [3,4], which is known to achieve highest precision and thus benchmark quality at both the DFT [5] and GW [6,7] levels. exciting implements the linearized augmented planewave method, which is the gold standard for solving electronic-structure problems. The outcome of this project will be a set of calculations that will serve to assess the impact of the method (DFT versus GW) and the probed computational parameters on the respective results. This, in turn, will be a valuable input for building the recommender system. This work is carried out in the framework of the CRC FONDA – Foundations of Workflows for Large-Scale Scientific Data Analysis.
 

[1] NOMAD https://nomad-lab.org
[2] M. Scheidgen, L. Himanen, A. Noe Ladines, D. Sikter, M. Nakhaee, A. Fekete, T. Chang, A. Golparvar, J. A. Marquez, S. Brockhauser, S. Brückner, L. M. Ghiringhelli, F. Dietrich, D. Lehmberg, T. Denell, A Albino, H. Näsström, S. Shabih, F. Dobener, M. Kühbach, R. Mozumder, J. Rudzinski, N. Daelman, J. M. Pizarro, M. Kuban, P. Ondracka, H.-J. Bungartz, and C. Draxl, NOMAD: A distributed web-based platform for managing materials science research data, J. Open Source Softw. 8, 5388 (2023).
[3] A. Gulans, S. Kontur, C. Meisenbichler, D. Nabok, P. Pavone, S. Rigamonti, S. Sagmeister, U. Werner, and C. Draxl, exciting: a full-potential all-electron package implementing density-functional theory and manybody perturbation theory, J. Phys.: Condens. Matter (Topical Review) 26, 363202 (2014). https://exciting-code.org
[4] V. Gavini, S. Baroni, V. Blum, D. R. Bowler, A. Buccheri, J. R. Chelikowsky, S. Das, W. Dawson, P. Delugas, M. Dogan, C. Draxl, G. Galli, L. Genovese, P. Giannozzi, M. Giantomassi, X. Gonze, M. Govoni, A. Gulans, F. Gygi, J. M. Herbert, S. Kokott, T. D. Kühne, K.-H. Liou, T. Miyazaki, P. Motamarri, A. Nakata, J. E. Pask, C. Plessl, L. E. Ratcliff, R. M. Richard, M. Rossi, R. Schade, M.
Scheffler, O. Schütt, P. Suryanarayana, M. Torrent, L. Truflandier, T. L. Windus, Q. Xu, V. W.-Z. Yu, and D. Perez, Roadmap on Electronic Structure Codes in the Exascale Era, Modelling Simul. Mater. Sci. Eng. 31, 063301 (2023)
[5] A. Gulans, A. Kozhevnikov, and C. Draxl, Microhartree precision in density functional theory calculations, Phys. Rev. B 97, 161105(R) (2018).
[6] D. Nabok, A. Gulans, and C. Draxl, Accurate all-electron G0W0 quasiparticle energies employing the full-potential augmented planewave method Phys. Rev. B 94, 035418 (2016).
[7] R. R. Pela, C. Vona, S. Lubeck, B. Alex, I. G. Oliva, and C. Draxl, Critical assessment of G0W0 calculations for 2D materials: the example of monolayer MoS2, npj Comput Mater 10, 77 (2024).