Regensburg 2025 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 16: Organic Semiconductors
HL 16.2: Talk
Tuesday, March 18, 2025, 09:45–10:00, H14
Accurate ab-initio parametrization of electron-phonon coupling models with Gaussian and plane-wave basis sets — •Konrad Merkel1, Maximilian Dorfner1, Manuel Engel2, and Frank Ortmann1 — 1TUM School of Natural Sciences, TU Munich, Germany — 2VASP Software GmbH, Vienna, Austria
For the simultaneous treatment of electronic and vibrational degrees of freedom, the Holstein-Peierls model has become a cornerstone in various scientific communities due to its versatility and remarkable success in the accurate description of materials. To use it, one needs to calculate all model parameters for the electronic structure, phonons and electron-phonon coupling constants. In particular, the calculation of the electron-phonon coupling constants is a challenge as they involve both degrees of freedom. Although various approaches exist, comprehensive benchmarks comparing different methods and basis sets are still rare. In our study, we investigate two different methods to calculate the electron-phonon couplings. The first approach was developed by Engel et al. [1] and is based on the projector-argumented-wave formulation and maximally localized Wannier functions and is implemented in the VASP code. The second approach is based on a real-space description in terms of Gaussian basis functions and is implemented using cp2k. Both approaches use a finite-displacement and finite-difference scheme to calculate the coupling constants. We compare both methods using different molecules and discuss critical points for accurate calculations.
[1] Physical Review B 106, 094316 (2022)
Keywords: electron-phonon coupling; ab-initio simulation; model parameter; Holstein-Peierls; Wannier function