Spex

Spex can calculate quasiparticle properties (one-shot and self-consistent) using the GW [1-10], GT [11,12], and GWT approximation [13] for the self-energy, EELS [2,14] and optical spectra as well as total energies in the RPA approximation [15], and spin-wave [16-19] and optical spectra (experimental) from the Bethe-Salpeter equation, Hubbard U parameters [20-22], Wannier interpolation, and more.

To download Spex, please register here
For further questions about the Spex code, write to spex-users@fz-juelich.de

1. C. Friedrich, S. Blügel, and A. Schindlmayr, "Efficient implementation of the GW approximation within the all-electron FLAPW method", Phys. Rev. B 81, 125102 (2010); 104, 039901(E) (2021). .
2. C. Friedrich, A. Schindlmayr, and S. Blügel, "Efficient calculation of the Coulomb matrix and its expansion around k=0 within the FLAPW method", Comput. Phys. Commun. 180,
   347 (2009).
3. C. Friedrich, M. C. Müller, and S. Blügel, "Band convergence and linearization error correction of all-electron GW calculations: The extreme case of zinc oxide", Phys. Rev. B 83, 081101 (2011); 84, 039906(E) (2011).
4. R. Sakuma, C. Friedrich, T. Miyake, S. Blügel, and F. Aryasetiawan, "GW calculations with spin-orbit coupling: application to Hg chalcogenides", Phys. Rev. B 84, 085144 (2011).
5. C. Friedrich, M. Betzinger, M. Schlipf, S. Blügel, and A. Schindlmayr, "Hybrid functionals and GW approximation in the FLAPW method", J. Phys.: Condens. Matter 24, 293201 (2012).
6. I. Aguilera, C. Friedrich, G. Bihlmayer, and S. Blügel, "GW study of topological insulators Bi2Se3, Bi2Te3, and Sb2Te3: beyond the perturbative one-shot approach", Phys. Rev. B 88, 045206 (2013).
7. I. Aguilera, C. Friedrich, and S. Blügel, "Spin-orbit coupling in quasiparticle studies of topological insulators", Phys. Rev. B 88, 165136 (2013).
8. I. Aguilera, C. Friedrich, and S. Blügel, "Electronic phase transitions of bismuth under strain from relativistic self-consistent GW calculations", Phys. Rev. B 91, 125129 (2015).
9. I. Nechaev, I. Aguilera, C. Friedrich, E. V. Chulkov, and S. Blügel, "Many-Body Effects in the Electronic Structure of Topological Insulators" in Topological Insulators: Fundamentals and Perspectives, ed. Frank Ortmann, Stephan Roche, Sergio O. Valenzuela, ISBN: 978-3-527-33702-6 (Wiley 2015).
10. D. Nabok, S. Blügel, and C. Friedrich, "Quasiparticle self-consistent GW study of simple metals", Nanomaterials, 12, 3660 (2022)
11. M. C. T. D. Müller, C. Friedrich, and S. Blügel, "Electron-magnon scattering in elementary ferromagnets from first principles: lifetime broadening and band anomalies", Physical Review B 100, 045130 (2019).
12. C. Friedrich,"Tetrahedron integration method for strongly varying functions: Application to the GT self-energy", Phys. Rev. B 100, 075142 (2019).
13. D. Nabok, S. Blügel, and C. Friedrich, "Electron-plasmon and electron-magnon
    scattering in ferromagnets from first principles by combining GW and GT self-energies", npj Comput. Mater. 7, 178 (2021).
14. S. Rost, S. Blügel, and C. Friedrich, "Efficient calculation of k-integrated electron energy loss spectra: Application to monolayers of MoS2, hBN, and graphene", Phys. Rev. B 107, 085132 (2023).
15. M. Betzinger, C. Friedrich, A. Görling, and Stefan Blügel, "Precise all-electron dynamical response functions: Application to COHSEX and the RPA correlation energy", Phys. Rev. B 92, 245101 (2015).
16. E. Sasioglu, A. Schindlmayr, C. Friedrich, F. Freimuth, and S. Blügel, "Wannier-function approach to spin excitations in solids", Phys. Rev. B 81, 054434 (2010).
17. C. Friedrich, E. Sasioglu, M. Müller, A. Schindlmayr, and S. Blügel, "Spin excitations in solids from many-body perturbation theory", Top. Curr. Chem. 347, 259-301 (2014).
18. M. C. T. D. Müller, C. Friedrich, and S. Blügel, "Acoustic magnons in the long-wavelength limit: Investigating the Goldstone violation in many-body perturbation theory", Phys. Rev. B 94, 064433 (2016).
19. C. Friedrich, M. C. T. D. Müller, and S. Blügel, "Many-body spin excitations in ferromagnets from first principles" in Handbook of Materials Modeling. Volume 1 Methods: Theory and Modeling, edited by S. Yip and W. Andreoni (Springer Berlin Heidelberg, 2018).
20. E. Sasioglu, C. Friedrich, and S. Blügel, "Effective Coulomb interaction in transition metals from constrained random-phase approximation", Phys. Rev. B 83, 121101(R) (2011).
21. T. O. Wehling, E. Sasioglu, C. Friedrich, A. I. Lichtenstein, M. I. Katsnelson, and S. Blügel, "Strength of effective Coulomb interactions in graphene and graphite", Phys. Rev. Lett. 106, 236805 (2011).
22. E. Sasioglu, C. Friedrich, and S. Blügel, "Strength of the effective Coulomb interaction at metal and insulator surface", Phys. Rev. Lett. 109, 146401 (2012).